FOR THE STOCK 4 onions or leeks, roughly chopped 3 celery stalks, roughly chopped 2 carrots, cut into chunks 4 bay leaves 1 long strip of lemon peel 1 tsp peppercorns 1 litre fish stock FOR THE TUNA CAKES 1 tbsp oil 1 onion, finely chopped 380g canned tuna, drained 1 egg 1-2 slices bread, soaked in milk Chopped parsley or grated lemon zest Cornflour, for coating 1 In a pan, bring all the ingredients for the stock to the boil, then lower the heat and simmer for 30 minutes. Prep time 10-15 mins Cooking time 30-45 mins Serves 4 2 To make tuna cakes, heat the oil and fry onion until soft. Add the remaining ingredients, except cornflour, and mix. Take the mixture off the heat and leave to cool. 3 Make lemon-size balls and chill until firm. 4 Strain the stock into a clean pan and bring it back to a simmer. Roll each tuna ball in cornflour and carefully drop them into the simmering stock. Let the cakes poach for 5 minutes or until firm. Drain and serve with salsa.