1. If using whole sausage remove meat from skins.
2. Grate/shred the carrots.
3. Puree the tin of tomatoes.
4. Heat the oil and butter in a saucepan and cook the onion until translucent.
5. Add the sausage meat and lightly brown, breaking it up with a fork.
6. Add the carrot and stir for a few minutes.
7. Add the tomatoes, stock bay leaf and oregano and cook, covered over a low heat for 30 minutes.
8. Taste for seasoning-if the sausages are spicy you may not need any.
9. Cook and drain pasta.
10. Mix pasta with the sauce and serve.
11. Serve cheese separately.