1 For the Fish Balls: Cut the cod fillet into rough chunks and place into the bowl of a food processor with the prawns. Blend to a coarse paste, break in the egg, add some seasoning and whiz again until you have a smooth mixture. 2 Scrape the mixture into a bowl and stir in the crabmeat, breadcrumbs, basil and lemon zest. Shape into small balls and leave to chill in the fridge while you make the sauce. 3 For the Tomato Sauce: Heat the olive oil and garlic in a pan. When sizzling, add the onion and cook until softened. Add the tomatoes, vinegar, thyme and bay leaves and simmer for 20 minutes. 4 Boil a pan of well-salted water. Drop the pasta into the boiling water and cook for 8-10 minutes until al dente. Pass the sauce through a conical sieve into a shallow pan, pressing out the liquid using a small ladle. 5 Stir the fish balls into the sauce and leave to simmer for 4-5 minutes until cooked through. Taste the sauce and adjust the seasoning if necessary. 6 To serve, drain the tagliatelle and divide between four bowls. Spoon the fish balls and sauce on top and serve garnished with a little more shredded basil and some finely grated parmesan cheese. Recipe by: Rick Stein