Wash fish, pat dry, sprinkle salt and pepper.
Heat oil on medium fire, fry fish both sides, hal-fry only. Set aside.
On the same pan, saute garlic, then onion.. Stir fry till luminous then put tomatoes. Stir, leave till becomes juicy. Season with back pepper and salt. Put back the fish and simmer uncovered for 12 minutes..
N.B. Some may want their fish to be more juicier.. I put 1 tbsp of tomato sauce and a cup of water while cooking the tomatoes before putting the fish. Don't add water when the fish is already cooking, it will become soggy.