There are two simple tricks to remember when preparing and cooking fish. The first is to select a cooking method that suit’s the type of fish you are using, the second is having the confidence to know when the fish is cooked. Oily fish such as mackerel or salmon have their natural oils distributed throughout the flesh, therefore they can stand the heat of a barbecue, grill or oven. The oils in white fish however are stored in the liver as apposed to the flesh, this makes them prone to drying out when cooked. Gentle cooking such as poaching or steaming is much better. Also oily fish suit strong accompanying flavours such as chilli, garlic and citrus sauces. White fish suit simple flavours such as herb butter or olive oil. Cooked fish loses its translucence, becoming flaky and opaque. Check the thickest part of the fish as this will take the longest to cook. Press the flesh of a fish fillet, it will loose its flabbiness when cooked. Tug the dorsal fin of a whole fish, that’s the one on the back, if it comes away easily then it is cooked. Or make a slit into the fish through the skin, lift the flesh away from the bone with a flat knife and it should be juicy and opaque. How to poach. Poaching keeps fish moist and tender. Poach whole fish such as salmon in a ‘court bouillon’, that is water with added vinegar, onion, carrots, celery, peppercorns and bay leaves. White or smoked fish is best poached in milk, thinned with a little water and flavoured with peppercorns, bay leaf, parsley and butter. For a meltingly tender result you can poach fish in flavoured olive oil. How to bake. Unlike meat and poultry fish does not benefit from a high oven temperature. Cook uncovered fish at around 160° C gas mark 3. A fillet should take around 10 to 15 minutes to cook. Brush delicate white fish with a flavoured oil or butter before baking. To obtain a crispy skin sear the fish in a frying pan first and then finish it in the oven. Fish may be baked inside parchment or foil, encased within a pastry case or stuffed with rice or vegetables. How to grill. Grilling seals in moisture and flavour. Place skin side up to protect the flesh from direct heat. Baste with flavoured oil or butter. Cook for 3 to 8 minuets. Thin fillets will not require cooking on both sides. Turn larger fillets only once, being careful not to damage the flesh. Slit the sides of whole fish before grilling to ensure that the centre cooks. How to pan-fry or griddle. This method is quick. Do not remove the skin prior to cooking. Dust in seasoned flour before cooking for an extra crunch. Cook for 2 to 4 minutes on each side, skin side first to help maintain shape. Use only a small amount of oil in the pan. Make sure a griddle in smoking hot, and oil the fish rather than the griddle. Tuna and salmon steaks may be seared so that they are still rare in the centre. How to deep-fry. Do not deep-fry oily fish. Use only a clean groundnut or sunflower oil. Cook at 180° C. The contrast between crisp batter and delicate fish is a delight. Batter helps retain a fishes flavour moisture. Breadcrumbs provide crunch, but do not protect the fish as well as a batter. A 2cm thick piece of cod should take 8 minutes to cook. How to stir-fry. This is the quickest method of cooking fish. Use a wok with very little for best results. Use thinly sliced or diced fish and stir continually during cooking. Add cooked rice or vegetables towards the end of cooking. How to barbecue. Whole oily fish barbecue well. Leave the skin on and salt prior to use, basting with a sauce or flavoured oil during cooking. White fish is best soaked in an oil based marinade prior to cooking, this protects the flesh. Foil wrap larger fish such as salmon, cooking for around 30 minutes and then removing the foil, allowing the skin to Crispin. How to steam. The gentle simplicity of steaming suits fish. It maintains moisture and seals in vitamins. Bamboo steamers work well.