Combine the lime rind, lime juice, olive oil, coriander and parsley in a large bowl. Add the fish and turn to coat in the marinade. Cover and place in the refrigerator for 30 minutes.
Place the pepper halves cut side down on a foil-lined tray. Grill under a high heat until well blackened. Remove from the oven, cover with a clean towel and when cool enough to handle, peel off the charred skin and dice the flesh.
In a large bowl combine the spring onion, diced red pepper, cantaloupe, parsley, coriander, sugar, olive oil and lime juice. Season if wished with salt and pepper.
Heat a dash of oil in a pan and cook the fish for about 3 minutes on each side until lightly browned and cooked through. Always place the fish down into the pan on the side you wish to serve to your guests. Serve the fish on salad greens topped with the melon salsa and boiled new potatoes.