2.Add tuna, pasta sauce, capers and juice to onions. Cook, stirring, 2-3 minutes, until heated through.
3.Cook fettuccine in a large saucepan of boiling water following packet instructions. Drain, reserving a little of the cooking liquid.
4.Spoon tuna mixture and spinach onto the cooked pasta and toss until well combined.
5.Serve pasta with extra fried capers, dill and lemon wedges.
It is important to stir the pasta once or twice after adding to the boiling water to help prevent sticking – a few drops of oil added to the water is a good idea too.