Wash and peel the onion. Keep the root end intact as that will help keep the onion from falling apart. Halve the onion vertically (through the root end and the top).
Peel the garlic and slightly crush under the side of a knife
Place all the ingredients, except the fusilli, in a saucepan and place over a medium heat.
Cook for 45 minutes, stirring occasionally.
Adjust seasoning if necessary.
When cooking is complete, remove the onions.
Cook the fusilli pasta as per the instructions on the packet (something like 5-7 minutes in salted water).
Drain the pasta, add it to the sauce, and stir to coat.
Serve topped with some freshly grated or shaved Parmigiano-Reggiano or Parmesan.