Sprinkle the sea bream fillets with the red chilli powder, salt and lime juice and set aside to marinate for 30 minutes.
For the spice crust, pound the shallots, garlic and peppercorns to a coarse paste in a pestle and mortar. Add the rest of the ingredients and mix well.
Heat the banana leaves in a hot frying pan until they are soft and pliable (or heat them in a microwave for about 30 seconds). Cover the bream fillets on both sides with the spice crust, wrap each one in a banana leaf, then set aside.
For the chutney, put all the ingredients in a food processor and blend to a smooth paste, adding a little more water if required.
To cook the fish, heat the tablespoon of oil in a heavy-based frying pan. Place the wrapped-up bream fillets in the pan, then cover and cook over a low heat for 3–5 minutes on each side.
Remove the leaves and serve the bream with the chutney.