Heat the oil in a frying pan over a medium heat, add the onion and garlic and cook for 3-4 minutes. Add the chopped tomatoes, white wine and chilli, season with salt and pepper and simmer for 8–9 minutes.
Cook the tagliatelle in a large pan of boiling water for 9–12 minutes, or according to the pack instructions.
Meanwhile, add the mussels to the tomato sauce, cover and cook for 4 minutes, until all the shells are open (discard any mussels that do not open).
Drain the tagliatelle and stir into the tomato sauce with the crab meat, lemon juice and parsley. Mix well and serve immediately.