Place fish fillets (skin side down if not skinned) into an ovenproof dish big enough that they don’t overlap. Mix the lemon juice, 1 tbsp olive oil and 2 tsp of fish seasoning together and spread evenly over the fish. Grind over some black peppercorns (quantity to suit). Allow to marinate for at least 30 minutes.

Preheat oven to 230C / 450F / gas mark 8

Mix the breadcrumbs with the remaining fish seasoning and olive oil (the oil with soak disappear quickly, but give the mixture a good mix to distribute it around as well as you can). Cover the fish with a layer of breadcrumbs pressing down well to make a firm crust. Take the butter and dot it ,in small pieces, all over the breadcrumb crust.

Bake in the oven for 8 – 10 minutes. The exact cooking time will vary a little depending on the thickness of your fillets.