Thai Coconut Chicken Soup: Tom Kha Gai the Way It’s Made in Korat

NOTE FROM SUSIE

Sawasdee Kha, and Hello.

My mother made this on cold nights. Not that Korat gets truly cold — but there were nights when the air shifted and she’d reach for the coconut milk without being asked.

The galangal went in first. She’d bruise it with the flat of her knife the same way every time. Three hard presses. The smell that came off it was nothing like ginger — sharper, almost medicinal, and then underneath that something floral. I’ve never been able to describe it exactly. I stopped trying.

The lemongrass came next. Bent and bruised at the stalk. Then the kaffir lime leaves, torn down the center so the oils released. By the time the coconut milk went in the kitchen already smelled like the soup. That’s how you know the aromatics did their job.

She’d taste it once before she brought it to the table. Just once. Then she’d set it down and sit and that was that.

I make this now when I miss her most. It doesn’t fix anything. But it helps.

WHAT IS THAI COCONUT CHICKEN SOUP?

Tom Kha Gai (ต้มข่าไก่) translates simply as boiled galangal chicken. The name undersells it. This is one of Thailand’s most recognized soups — a coconut milk broth built on three aromatics that don’t exist anywhere else in the world together: galangal, lemongrass, and kaffir lime leaves. They’re not interchangeable with anything. They are the dish.

Tom Kha Gai originated in northern Thailand and Laos, where galangal — kha in Thai — grows abundantly. It moved south and became a staple across the country, but the northern roots show in the broth’s restraint. It isn’t loaded with chili paste the way some Thai soups are. The heat is quiet. The sourness comes from fresh lime juice added at the end, and from fish sauce that lifts everything without dominating.

What makes thai coconut chicken soup different from a curry is the broth itself — thin, not thickened, meant to be sipped as much as eaten. The coconut milk enriches without smothering. The Culinary Institute of America notes galangal as one of the defining flavors of Southeast Asian cuisine — and in this soup, you understand exactly why.

The first sip tells you everything. Rich and sour and faintly floral. All at once.

WHAT YOU’LL NEED

Galangal is the non-negotiable. Not ginger — galangal. The two look similar in the store but they are entirely different. Galangal is harder, denser, with a piney, almost medicinal quality that ginger cannot replicate. You’ll find it fresh or frozen at any Asian grocery store. Slice it thin and bruise each piece before it goes in. You won’t eat the slices — they’re too fibrous — but they’ll give everything to the broth.

Lemongrass. one stalk, outer layers peeled away, cut into two-inch pieces and bent or bruised at the stalk so the oils release. Same rule applies — you’re not eating it, you’re extracting from it.

Kaffir lime leaves — six to eight, torn down the center spine. That tearing releases the citrus oils. Don’t skip it. Don’t substitute regular lime zest. It isn’t the same thing. Find kaffir lime leaves fresh or frozen; they keep in the freezer for months.

Coconut milk — one full can, full fat. Not light. The richness is the point. A good Thai brand like Aroy-D or Chaokoh makes a difference here. Thin, watery coconut milk will give you a thin, watery soup.

Chicken — boneless breast cut into bite-size pieces. breast stay tender in the broth where breast meat dries out. One pound feeds four people comfortably.

Chicken broth, two cups. Fish sauce, three tablespoons — start there and adjust. Fresh lime juice at the end, not bottled. Thai bird’s eye chilies, two or three, lightly bruised — optional but traditional. Oyster mushrooms or straw mushrooms, a handful, pulled apart by hand.

Fresh cilantro and sliced scallion for serving. A drizzle of chili oil if you want heat.

For a lighter companion to this soup, try my Thai Rice Soup — same patience, completely different bowl.

VISUAL WALK THROUGH

Step 1: Prepare the Aromatics

Slice the galangal thin. Bruise each piece with the flat of your knife — three firm presses. Peel the outer layers from the lemongrass, cut into two-inch pieces, and bend each piece hard until it cracks. Tear the kaffir lime leaves down the center spine. Set everything together on the board. The smell at this point will tell you something important is about to happen.

Step 2: Simmer the Aromatics in Broth

Pour the chicken broth into a medium pot over medium heat. Add the galangal, lemongrass, and kaffir lime leaves. Bring to a low simmer and let the aromatics steep for five minutes. Don’t rush this step. The broth is building its foundation.

Step 3: Add the Coconut Milk

Pour the coconut milk in slowly, stirring as it goes. Keep the heat at medium-low. You are not boiling this soup — you are warming it. A hard boil breaks the coconut milk and the broth turns grainy and flat. Low and slow keeps it silky. Watch for the moment the broth turns from pale gold to ivory. That’s where you want to stay.

Step 4: Add Chicken and Mushrooms

Add the chicken pieces and mushrooms directly to the simmering broth. Cook for eight to ten minutes on medium-low until the chicken is just cooked through. Don’t overcook — thebreast will stay tender if you pull them at the right moment. Test one piece before you season.

Step 5: Season and Finish

Add the fish sauce and stir. Taste. Add more fish sauce one teaspoon at a time if it needs salt. Squeeze the lime juice in last — this is what brightens everything and lifts the richness of the coconut milk. Taste again. Ladle into warm bowls, scatter fresh cilantro and sliced scallion, and serve immediately.

Thai Coconut Chicken Soup(Tom Kha Gai)

Susie Thompson

Tom Kha Gai — thai coconut chicken soup built on three aromatics that don't exist anywhere else in the world together. Galangal, lemongrass, kaffir lime leaves, coconut milk. The broth is silky and sour and faintly floral. My mother made this on the nights the air shifted. I make it on the nights I miss her.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 30 minutes mins

Total Time 50 minutes mins

Course Appetizer, Family meal, Main Course, Soup, Soup and Stews

Cuisine Thai, Thai/Central

Servings 4 people

Calories 380 kcal

Equipment

• Medium heavy pot
• Sharp knife
• Ladle

Ingredients

  

1x2x3x

• 2 cups coconut milk
• 2 cups chicken broth use vegetable broth for a vegetarian version
• 1 pound chicken breast thinly sliced (or use equivalent amount of mushrooms for a vegan version)
• 1 stalk lemongrass cut into 2-inch pieces and smashed
• 3 slices galangal about ¼ inch thick
• 5 kaffir lime leaves torn into pieces (remove stem)
• 3 tablespoons fish sauce substitute soy sauce for a vegetarian version
• 2 tablespoons lime juice
• 1 teaspoon sugar
• 3 Thai chilies smashed (adjust based on your heat preference)
• ½ cup sliced onions
• 1 cup sliced mushrooms optional if using chicken
• ¼ cup cilantro chopped for garnish
• Optional: cherry tomatoes and/or red bell pepper slices for added color and texture

Instructions

 

Cook ModePrevent your screen from going dark

Prepare the Ingredients:

• Chicken and Mushrooms:

  Rinse the chicken breast under cold water and pat it dry with paper towels. Place it on a cutting board and slice it against the grain into thin strips about 1/4 inch thick. If using mushrooms, clean them with a damp cloth or by quickly rinsing and patting them dry. Slice them thinly.
• Lemongrass:

  Cut off the root end of the lemongrass stalks and remove any tough outer layers until you reach the tender, pale yellow part. Cut the lemongrass into 2-inch pieces. To release its flavor, lay each piece flat on a cutting board and gently crush it with the back of a knife or a rolling pin.
• Galangal and Thai Chilies:

  Peel the galangal and slice it thinly into rounds. Use about 4-5 slices, depending on their size. Thai chilies can vary in heat; if you prefer a milder soup, remove the seeds before smashing them with the flat side of a knife.
• Prepare the Broth:

  In a large pot, pour the chicken broth and add 1 cup of coconut milk. Place the pot over medium heat and stir gently until the coconut milk is fully incorporated into the broth. Bring the mixture to a gentle simmer, stirring occasionally to prevent sticking.
• Infuse the Broth:

  Once the broth is simmering, add the prepared lemongrass pieces, sliced galangal, kaffir lime leaves (torn slightly to release flavor), and smashed Thai chilies to the pot. Stir gently to distribute the ingredients evenly in the broth. Allow them to simmer together for about 5 minutes. This step allows the herbs to infuse the broth with their aromatic flavors.
• Introduce the Chicken and Vegetables:

  Carefully add the sliced chicken (or mushrooms) and the sliced onion to the simmering broth. Stir gently to combine. Pour in the remaining coconut milk, which adds richness to the soup. Adjust the heat slightly to maintain a gentle simmer.
• Cook Until Tender:

  Continue to simmer the uncovered soup, stirring occasionally, until the chicken is fully cooked and no longer pink inside (about 10-15 minutes for chicken). If using mushrooms, they should be tender and cooked through.
• Balance the Flavors:

  Stir in the fish sauce, starting with a tablespoon and adjusting to taste. Fish sauce adds depth and saltiness to the soup. Add the sugar to balance the flavors and the freshly squeezed lime juice for a touch of acidity. Taste the soup and adjust the seasoning as needed by adding more fish sauce for saltiness or lime juice for acidity.
• Optional Vegetables:

  Add cherry tomatoes and thinly sliced red bell pepper to the simmering soup if desired. Cook for 2-3 minutes until the tomatoes soften, and the bell pepper slices are tender-crisp. This step adds color and freshness to the soup.
• Remove Aromatic Herbs:

  Remove the pot from the heat once the soup is fully cooked and seasoned to your liking. Using tongs or a slotted spoon, carefully remove and discard the slices of galangal, lemongrass pieces, kaffir lime leaves, and any smashed Thai chilies. This ensures the soup remains smooth and pleasant to eat without biting into large pieces of herbs.
• Garnish and Serve Hot:

  Ladle the aromatic Tom Kha Gai into bowls. Garnish each serving generously with freshly chopped cilantro leaves, which add a final burst of herbal fragrance and color. Serve the soup hot, allowing the flavors to unfold fully with each spoonful.
• Enjoy Immediately:

  Serve the Tom Kha Gai immediately after garnishing. This ensures the soup is enjoyed at its best hot, flavorful, and comforting.

Notes

The aromatics go in bruised and whole, not chopped. You are steeping them like tea — drawing out their oils and their fragrance into the broth. They come out before serving. If someone bites into a piece of galangal expecting ginger, they’ll be surprised. Warn your guests or remove everything carefully before you ladle.

Do not boil this soup. Medium-low heat the entire way through. Coconut milk splits at a hard boil and the texture turns grainy and unpleasant. If you see it starting to bubble aggressively, pull the heat down immediately. The soup should move gently. That’s all it needs.

Fish sauce goes in before the lime. Always. Season with fish sauce first, then brighten with lime at the very end. If you add the lime too early it loses its freshness and the sour note flattens into the broth instead of sitting on top of it where it belongs.

This thai coconut chicken soup is better the next day. The galangal and lemongrass deepen overnight in the refrigerator. Reheat it gently over low heat and add a fresh squeeze of lime before serving. Don’t boil it reheating either. Same rule. Always the same rule.

Nutrition

Serving: 4ServingsCalories: 380kcalCarbohydrates: 10gProtein: 28gFat: 26gSaturated Fat: 17gCholesterol: 85mgSodium: 860mgPotassium: 620mgFiber: 1gSugar: 5g

Keyword Coconut Soup, Thai coconut soup, tom kha gai recipe,

Tried this recipe?Let us know how it was!

LET’S GET THIS RIGHT

Why does my thai coconut chicken soup taste flat?

The lime juice went in too early or didn’t go in at all. Lime is what lifts the richness of the coconut milk and makes the soup taste alive. Squeeze it in at the very end, after the heat is off, and taste immediately. If it still tastes flat, add more fish sauce one teaspoon at a time — flat usually means under-seasoned, not under-spiced.

Can I substitute ginger for galangal?

You can, but the soup will be a different dish. Galangal has a piney, floral quality that ginger doesn’t carry. Ginger is warmer and more assertive. The soup will still be good. It won’t be Tom Kha Gai. If you’re making this for the first time, make the trip to the Asian grocery store and find the real thing.

Why did my coconut milk break and turn grainy?

The heat was too high. Coconut milk splits at a hard boil. Keep it at medium-low the entire time — a gentle simmer, nothing more. If it breaks, lower the heat immediately, add a splash of fresh coconut milk, and stir slowly. It won’t fully recover but it will come back enough to serve.

Do I eat the galangal and lemongrass?

No. They’re too fibrous. They go in to flavor the broth and come out before serving, or you leave them in and eat around them. Most Thai households leave them in — everyone knows to push them to the side. Your call.

My soup is too sour. How do I fix it?

Add a small amount of coconut milk or a pinch of palm sugar and stir gently over low heat. The sweetness will round out the sour without erasing it. Add slowly and taste after each addition. You can’t take sourness out but you can balance it.

FLAVOR PROFILE

The first thing is the smell. Before the bowl reaches the table. Lemongrass and galangal coming off the steam, faintly citrus, faintly medicinal, something you can’t name exactly but recognize immediately as Thailand.

The first sip is rich. Coconut milk coats the back of the throat. Then the sour arrives — lime and fish sauce together, bright and clean against all that richness. The galangal is underneath everything, quiet and piney. The kaffir lime leaf is even quieter. You wouldn’t know it was there if it wasn’t.

The chicken is tender. The mushrooms have absorbed the broth and give it back with every bite. The chili, if you added it, arrives last. A slow heat that builds and then fades.

Thai coconut chicken soup doesn’t shout. It settles. And then it stays with you for the rest of the evening.

SUSIE’S KITCHEN NOTES

Buy your coconut milk in cans, not cartons. Carton coconut milk is diluted and processed for drinking — it doesn’t have the fat content or the body that a soup like this needs. Full-fat canned coconut milk only. Shake the can before you open it. If it sounds thin and watery, it probably is. Aroy-D and Chaokoh are the brands I trust.

The order matters. Aromatics in broth first, steep, then coconut milk, then chicken. If you add the coconut milk too early and then bring everything up to temperature together, the galangal and lemongrass don’t have enough time to give the broth what they have. Five minutes of steeping in plain broth before the coconut milk arrives makes a real difference.

Kaffir lime leaves freeze beautifully. Buy a bag, use what you need, freeze the rest in a zip-lock. They go straight from freezer to pot — no thawing needed. Same with galangal. These ingredients can be hard to find fresh consistently, but frozen works just as well in a cooked dish like this.

If you want more heat, add the bird’s eye chilies whole and bruised at the beginning with the other aromatics. They’ll give the broth a steady warmth without making the soup aggressively spicy. For serious heat, slice them. For a hint, leave them whole and remove before serving.

PAIRING SUGGESTIONS

Thai coconut chicken soup is rich enough to be a meal on its own, but it pairs naturally with jasmine rice— the plainness of the rice gives the broth somewhere to go. A plate of Thai cucumber salad alongside it does what a good salad always does: cuts through the richness and resets the palate between spoonfuls. If you’re building a fuller table, Thai basil chicken brings the heat and the char that Tom Kha Gai doesn’t carry, and the two dishes together cover every register. Finish with bananas in coconut milk — the sweetness echoes the coconut in the soup and closes the meal gently.

FAQ