This dish comes together in the simplest way and is destined to quickly become a favourite. If cooking a whole fish feels daunting, ask your fishmonger to butterfly it for you, or experiment first with wild salmon fillets – just remember to cut the cooking time in half. It’s all about those buttery, garlicky, vinegared walnuts, after all.
1 whole rainbow trout, about
1 tbsp extra virgin olive oil
60g walnuts, roughly chopped
2 garlic cloves, finely minced
zest of 1 lemon, plus juice of ½ lemon
½ bunch parsley leaves
1 tbsp white wine vinegar
salt and pepper, to season
1. To prepare your fish, cut the head and tail off using a sharp knife. Wipe the skin with a damp cloth and season liberally with salt on both sides. Set aside.
2. Place a large, wide frying pan (non-stick if you have it) over medium heat. Add the olive oil and, when it's hot, place the fish in the pan. Cook for 6 minutes on each side then remove, allowing the fish to rest on a plate. Remove the pan from the heat.
3. Add the butter and walnuts to the same pan you cooked the fish in and set it over medium heat again. Stirring constantly, cook for two minutes, allowing the butter to brown and the nuts to toast. Quickly turn the heat off, add the garlic, lemon zest and most of the parsley and sizzle for 30 seconds before adding the lemon juice and white wine vinegar.
4. Using a paring knife, cut along the "back" of the fish, lift off the top fillet and set it on a serving platter. Then lift the backbone from the bottom fillet. All of the bones should come out easily. Trim off the top fins. Season the fish with a sprinkle of salt and pepper and serve with the warm, buttery walnuts spooned over the top. Garnish with the remaining parsley.