Prepare the flounder by cleaning and patting it dry. Score the fish and season with cooking wine, fine salt, and pepper.

Make a cross-cut on the tomato and blanch it in boiling water. Peel off the skin.

Finely chop the onion, garlic, and peeled tomato.

Heat 1 tbsp of butter in a pan and sauté the onion and garlic until fragrant.

Add the chopped tomato to the pan and continue sautéing.

Pour in 1/4 cup of water and add 1 tsp of oyster sauce. Simmer until the sauce thickens.

Coat the flounder evenly with frying flour.

Heat a generous amount of olive oil in a pan and fry the flounder until golden and crispy on both sides.