- Heat olive oil in a large saucepan and cook onion until soft.
- Remove sausage meat from casings and add to pan in pieces, breaking up with a wooden spoon.
- Stir and cook until no longer pink, but not browned. Stir in milk and simmer very gently, until mostly absorbed.
- Add tomatoes, maple syrup, nutmeg, salt and pepper. Simmer for about 20 minutes, stirring occasionally, until sauce thickens.
- Toss with pasta and serve with parmesan.