Saute slowly the onion, carrot and celery in the olive oil until well softened (at least 10 minutes). Add the garlic and chili just a few minutes before you finish the offritto (sauteed mixture).
Add the chopped tomatoes, the herbs and sugar. Season lightly with salt and pepper.
Allow to simmer gently, uncovered, for 30-40 minutes, until the oil begins to separate out into small drops around the edge. Stir occasionally to prevent the sauce sticking to the bottom.
Remove and discard the parsley stalks and the bay leaf. Push the sauce through the coarsest disc of a mouli legume, or blitz it for a few seconds in a food processor - or leave it as it is. Spoon the sauce back into the saucepan and keep it hot while you cook the pasta.
Cook the pasta in plenty of boiling salted water until al dente.
Drain well and toss with the sauce.
Serve at once, and hand round a bowl of freshly grated parmesan.
