Begin by melting the butter in a large flat bottomed pan with a little oil.

Thinly slice the leeks, add to the pan and stir until the leeks are completely coated in the butter.

Next, add the mushrooms and chestnuts to the pan, also thinly sliced and cook for 5 - 8 minutes until the mushrooms and leeks are tender and wilted.

Add the garlic to the pan and cook for a further five minutes.

Pour over the cream, stir in the parmesan and heat on low.

Put the pasta into a large saucepan and cover with boiling water. Cook for 10 minutes until al dente.

Drain the pasta and transfer to the pan with the cream sauce.

Stir through so that the sauce completely coats the pasta.

remove the leaves from your sprig of thyme, add to the sauce and cook for another 2 minutes.

Serve hot.