Boil the penne in salted hot water. Let them cook as instructed on the pack.

In a pan, heat the olive oil and add the chili flakes. Stir for 1-2 minutes until the flakes release their taste. Then add the onion and the garlic. Stir well until the onion softens.

Add the chopped tomatoes and season with salt and pepper. Stir again to mix the sauce and add the fresh leaves of basil. Cover the sauce and let boil for 2-3 minutes.

When the sauce is ready, mix with the cooked pasta and serve immediately.