Put the fish in a bowl.
Chop the chilli pepper into small segments and mix with the chilli flakes, lime juice, 3 cloves of finely chopped garlic and the salt.
Pour over the fish and leave to marinade for 30 minutes. After 30 minutes add the shrimp and leave to chill for 30 minutes longer.
Chop the onion, peppers and tomatoes and the rest of the garlic. Add to a pan.
Place the fish, parsley and shrimp on top and pour the olive oil over the top.
Bring to a boil and cover and simmer for 20 minutes until the fish is cooked.