Cut the onion finely and braise it in a little oil. Add the garlic and grated tomatoes. Leave the sauce to boil until the liquid evaporates.
Boil the bucatini (al dente) in salted water and strain them. Add them to the boiling sauce. Add the cherry tomatoes (cut in 2) and the spices.
Pour in a little of the water in which you boiled the pasta. Stir well and remove from the stove after 3-4 min. Serve the bucatini warm, sprinkled with parmesan.