Clean, gut and wash fish, cut into the desired size.
Place fish in a bowl, sprinkle salt and 2 seasoning cubes on it, mix well.
Slice the 150g onions and sprinkle some on the fish, set aside to marinate.
Reserve the other part of the sliced onions.
Remove seeds from tatashe, wash 350g onions, tomatoes, tatashe, shombo and scotch bonnet.
Blend to a smooth puree.
Mix with the tomato paste and set aside.
Pour palm oil into a dry pot and set over medium-high heat. When very hot, add the reserved sliced onions.
Fry until the onion begins to turn brown.
Pour in blended tomato, add seasoning cubes and salt, stir and leave to boil.
Boil until the stew has reduced and some oil starts to float on top of the boiling stew, about 20 minutes.
Add the fish with onions and 2 cups of water (the water cooks the fish without drying out the stew).
Gently shake and rotate the pot and push the fish in, submerging it in the stew, cover and cook until fish has softened about 10 minutes.
Taste and correct seasoning.
Take off the heat and enjoy.
Serve your Nigerian fish stew with boiled yam, plantain, sweet and Irish potato, any fufu of your choice paired with some steamed vegetables e.g okro, ewedu (jute leaves), spinach etc.