Pour the basil leaves into the mortar, add garlic, sea salt and grind into a smooth paste.
Score the fish and insert the paste into it, rubbing the remaining basil paste around the fish.
Cover with a cling film and set aside to marinate for 30 minutes.
Heat vegetable oil in a pan over medium heat, add flour, then carefully place the fish in.
Fry for 6 minutes on each side or until golden on all sides, take out of the oil and set aside.
Reduce ¾ of the oil, then add the sliced onions.
Fry for 10 minutes or until it turns brown (caramelized).
Add the scotch bonnet pepper, petite belle pepper, basil, stir in and let it sweat for 2 minutes, then add the fish stock, sea salt, stir and let simmer for 2 minutes.
Add the fried fish and let simmer on low heat for 3 minutes.
Fried fish in caramelized onions ready to serve.
NB; You can let the onion fry for long depending on how brown you want your caramelized onions, and the trick to caramelizing onions is not to stir often, else they won’t brown but not unattended to for so long so that they burn.