Heat oil in pan, add the onion and cook for a couple of minutes. Stir in the garlic, tomatoes, chilli and sugar. Season and bring to the boil. Stir, then reduce the heat and simmer for 5 minutes.

Meanwhile, bring a large pan of salted water to the boil. Add the pasta and cook according to packet instructions.

Flake the tuna into the sauce and heat through. Drain the pasta, return to the pan and stir in sauce and basil leaves. Serve with a generous grinding of pepper.