Preheat the oven to Gas Mark 4, 180°C (360°F). Wipe the fish fillets with kitchen paper to get them as dry as possible, then place them in a lightly oil roasting tin. Season with a little salt and black pepper. Mix the chopped coriander and capers into the mayonnaise. Add a little seasoning then spread the coriander mayo all over the top surface of the fish. Combine the breadcrumbs, cheese, coriander and lime rind and sprinkle this over the fish as evenly as possible. Place in the preheated overn for 10-15 minutes. When it is cooked the topping will be crispy and golden and the fish will flake easily with a fork.
Serve with steamed potatoes, tossed in chives, lemon juice and sautéed leeks.