Pasta with sausage, chestnuts and sage

Method

1. Bring a large pan of salted water to the boil. Meanwhile, heat the oil in a large, deep frying pan over a medium heat. Add the sausages and cook for 5 minutes until browned. Add the garlic, cook for 2-3 minutes, then stir in the tomato purée and cook for a further 30 seconds.
2. Add the pasta to the boiling water and cook for 9 minutes until al dente.
3. While the pasta cooks, add the wine to the sausage pan and simmer for 3 minutes, then pour in the stock and cook for 5 minutes. Stir in the chestnuts and cook for a final 2-3 minutes, then keep warm.
4. In a separate small frying pan, melt the butter and heat until it stops foaming. Add the sage leaves and fry for 2-3 minutes until crisp and the butter is nutty and brown.
5. Drain the pasta, reserving a cupful of cooking water, then add to the sausage mixture, tossing and adding enough pasta water to create a thick sauce. Divide among serving bowls and pour over the sage butter. Finish with parmesan.