Start to cook the pasta as per the pack instructions

Meanwhile, heat the oil and margarine in a pan over a medium heat and fry the onion until softened

Add the bacon and sliced mushrooms and cook until browning

Add the garlic and fry for 1 minute. The mushrooms should have released some liquid by now. If not, add an extra tbsp of oil or margarine

Add the flour and stir to coat. Cook for a minute then pour in the milk and add the peas

Bring to the boil then let simmer for 5 minutes or so until thickened

Add the cheese and let melt in then season the sauce to taste with black pepper

Remove from the heat and add the pasta back to the pan, stir to coat and warm through before serving topped with some extra 'parmesan'