No course in the art of using a knife is complete unless you learn how to fillet a fish. But with any good fishmonger happy to fillet a fish for you, why learn yourself? In a word: choice. If you have the opportunity to buy from a market or at the quayside, you can make more of your own decisions about the freshness, source and sustainability of the fish you cook. And if you are lucky enough to catch your own, there’s only one person who should be preparing it. It takes dexterity and – like most worthwhile things in life – a little practice, but boning a fish is easier than you think.
Don’t try to fillet a fish without an immaculately sharp knife. The way you will be turning and angling the blade makes it important to choose a design that sits comfortably in the hand and that you can manipulate easily. The quicker, river-fisherman’s technique depends on having a cutting edge at least as long as your fish is wide, but for most kitchens a six or seven-inch blade is adequate. Also, equip yourself with some tweezers – from the cosmetics shelf at the chemist’s, or a pair of professional-looking pincers. One tip is to salt your fingers before you start – this gives a better grip of the slippery skin.
Use this method to fillet a round-bodied fish like mackerel, haddock, John Dory, bass and bream, as well as river fish such as pike.
Place the fish pointing diagonally away from you, with its head on the opposite side to your cutting hand. Slice firmly around the head, just behind the gill, cutting through to the bone. Then, in a separate motion, run the knife from the back of the head, along the line of the backbone, all the way to the tail. Try to draw the knife smoothly and steadily. Lift up the flap you have made and, using the tip of the knife, gently separate the fillet from the bones, working your way from the backbone down to the fish’s underside. This is the moment to pull the fillet away and prepare it on its own. Shape it by trimming off any loose edges and clean out the pin bones using the tweezers.
Now turn the fish over and repeat. The second side is slightly more difficult and you will realise how helpful it was to have the flat but flexible base of the other fillet to stabilise you. However, having prepared one fillet already, your confidence will be growing.
A variant of this technique is to place the fish horizontally in front of you, again with the head on the opposite side to your cutting hand. Cut down behind the gills as before, but on hitting the bone, twist the knife so that the cutting edge is now heading back towards the tail. Press down on the fillet-to-be, keeping your hand as firm and flat as you can while also tucking your fingers in, so they are safely inside the fish’s outline and out of the way of the blade. Now work the knife back towards the tail.
To skin the fillets, place them skin side down, with the tail towards you. Make a neat, sharp cut at the tail-end, hold the skin as firmly and tautly as you can, and cut away from yourself – much depends on the tension at the point where skin, fillet and the blade’s edge all meet.
To fillet a flatfish, such as a halibut or sole, position the fish diagonally, as for a round-bodied fish. Remove the head and, using a good pair of kitchen scissors, trim off the fins and tail. Make your next cut along the lateral line of the fish and gently work the knife back out to the edge. Repeat for the other side, to cut what are, properly, half-fillets. Some flatfish yield two further fillets from the underside – a technique known as “quarter filleting”. Brave souls attempting to fillet a monkfish need to remove the fearsome-looking head, then loosen the skin at the other end with a knife and half-peel, half-slice it away.
Why not showcase your new-found skills with one of Maille’s exclusive recipes. Of course, it’s hard to improve on a classic dish of grilled trout, served with a dressing of crème fraiche and Dill, Lime and White Wine Mustard. Or you could simply brush a little of your favorite mustard on to a pan-fried cod steak. But for a distinctively delicious main course, try our monkfish blanquette. This firmer white fish has the perfect texture for a coconut and mild curry sauce, set off with a dash of White Wine Mustard fresh from the pump. Bon appétit!