Prepare the Ingredients: Crack the eggs into a bowl, then add the fish sauce, soy sauce, and white pepper. Whisk everything together until smooth and well combined. The fish sauce and soy sauce add a depth of umami flavor that is signature to Thai cuisine, while the white pepper adds a subtle heat. Finely chop the green onions and set them aside; they will add freshness and color to your omelet.

Heat the Oil: Pour the vegetable oil into a large frying pan or wok and heat it over medium-high heat until it's shimmering and hot. Hot oil is the key to a perfect Khai Jiao, which creates crispy edges. Ensure the oil is hot enough by dropping a small amount of the egg mixture into the pan; it should sizzle immediately.

Cook the Omelet: Pour the egg mixture into the hot oil simultaneously. The mixture will puff up and create crispy edges. Let it cook undisturbed for 1-2 minutes until the bottom is golden brown. Carefully flip the omelet using a spatula and cook the other side for 1-2 minutes. The omelet should be crispy on the outside and soft on the inside, with a beautiful golden color.