Step 1: Prepare the marinade. In a bowl, combine the soy sauce, fish sauce, brown sugar, tamarind paste, minced garlic, black pepper, ground coriander, and chili flakes (if using). Stir the ingredients thoroughly until the brown sugar completely dissolves.

Step 2: Marinate the Beef. Place the beef slices in a large bowl or a resealable plastic bag. You can use soy sauce, garlic, ginger, brown sugar, and some oil as a marinade. Make sure to evenly coat each piece of beef with the marinade to enhance the flavor. Once coated, seal the bowl or bag and refrigerate the beef for at least 4 hours to allow the flavors to penetrate the meat. For even better results, refrigerate it overnight for a more intense and delicious taste.

Step 3: Dry the Beef To prepare the beef jerky, preheat your oven to 175°F (80°C) or set up a drying rack in a sunny outdoor location. Take the meat out of the marinade and place it on a baking sheet lined with parchment paper, ensuring the pieces do not overlap. If using an oven, bake the beef for 3 to 4 hours, remembering to turn the pieces over halfway through. Alternatively, if air-drying outdoors, leave the meat in direct sunlight until it reaches the desired dryness, which may take a different amount of time depending on the weather conditions. Adjust the timing as needed until the jerky has the texture you prefer.