Peel the garlic and finely slice with the chilli (halve and deseed it first if you don’t want the sauce too hot). Pick the basil leaves off the stalks and put to one side. Finely chop the stalks. Cook the spaghetti in a large pan of boiling salted water according to packet instructions. Meanwhile, put a large saucepan on a medium heat and add 2 good lugs of oil. Add the garlic, chilli and basil stalks and give them a stir. When the garlic begins to brown slightly, add most of the basil leaves and scrunch in the tomatoes. Turn the heat up high and stir for 1 minute. Taste and season with sea salt and black pepper, if needed. Drain the spaghetti, reserving a mugful of cooking water, then transfer it to the pan of sauce and stir well. Add a splash of pasta cooking water to loosen, if needed, then taste and season to perfection. Divide the pasta between bowls, or put it on the table in a large serving dish and let everyone help themselves. Roughly tear over the remaining basil leaves and finely grate over the Parmesan.