Bring a pot of salted water to the boil and cook the pasta according to the instructions.
400 g macaroni pasta
When cooked, pour into a colander and run under cold water to stop them cooking.
Pour a little olive oil over the pasta to prevent it from sticking.
olive oil
Preheat the oven to 180ºC/ 350ºF/ Gas mark 4.
Place a pan over a high heat adding a little oil. Add the mushrooms and the butter and fry until the mushrooms are lovely and brown.
500 g mushrooms, 150 g unsalted butter, Vegetable oil
Using a separate pan over a medium heat add the remaining butter until it melts and add the flour.
150 g plain flour, 2 knobs unsalted butter
Cook for a minute or so and then gradually add the milk and continually stir.
1.5 litres milk
Once all the milk has been added and the sauce has come to a boil, turn off the heat and add the Cheddar and/or Gruyère and allow it to melt into the sauce.
150 g Gruyère, 150 g mature Cheddar
Season with salt and pepper.
salt, pepper
Taste the cheese sauce and add extra cheese or seasoning if required.
In the same pan, add the uncooked thinly sliced leeks, cooked mushrooms and the pasta to the cheese sauce.
2 large leeks
When fully mixed together, pour the mixture into an oven proof dish.
I like to add either grated Gruyère or Parmesan to the top of the mixture prior to cooking. It creates a lovely thin crust.
100 g Parmesan
Place in the middle of the oven and cook for 30–35 minutes until cooked through and golden brown.
Serve on warmed dishes with hot garlic bread for a superb filling meal.