Rinse the fish, pat it dry with kitchen paper and cut it into large chunks.
Grate the lime zest over the fish, drizzle over the lime juice and season with salt and freshly ground pepper. Set aside while you make the sauce.
Moqueca - The sauce
Heat a splash of oil in a large frying pan and fry the onion until soft and translucent.
Add the garlic, peppers, jalapeño and tomatoes and fry for 4-5 minutes, then sprinkle over the spices and stir well to combine.Season with salt and freshly ground pepper.
Add the tomato purée and cook for about a minute, then pour in the stock and coconut milk.
Let the sauce simmer gently for 5-8 minutes, or until it thickens slightly.Season to taste with salt and freshly ground pepper, and add chilli flakes if you would like it spicier.
Nestle the pieces of fish into the sauce, cover with a lid and cook until the fish is only just done - take care not to overcook it. Allow 5-8 minutes depending on the size of the pieces.
Serve your moqueca with cooked rice, fresh coriander or parsley and lime wedges, if you like.