Prepare your tilapia by properly removing its gills and scales, and washing.
On both sides of the fish, make 2 slits.
Rub about 1 teaspoon of tamarind base powder and allow to stand for 10 minutes.
Mix together tomatoes, onions, garlic, and remaining ginger tamarind powder in a bowl and stir. Add pepper and salt to taste and stir some more.
Scoop the above mixture and stuff inside the tilapia's cavity.
Brush both tilapias’ surface generously with butter.
Place the tilapia in an aluminum foil and wrap. To prevent leakage of juice, double the wrap.
Heat the cooking oil, around 2 cups in the pan over medium heat. Then put the fish and cover. Cook for about 5 minutes or until no more crackling sound s heard. Repeat on the other side.
Remove from pan, allow to cool for a bit to avoid sticking of the fish in the aluminum foil, and serve. Enjoy.