1: To make the cheese sauce, melt the butter in a large non-stick saucepan over a medium heat. Add the flour and cook, stirring with a wooden spoon, over a medium-low heat for 2–3 minutes. Gradually stir in the milk and bring to a gentle simmer.

2: Swap the spoon for a whisk and whisk until the sauce begins to thicken. Add the nutmeg, truffle and porcini paste, mushroom powder and all three cheeses. Stir until the cheeses have melted into the sauce, then remove from the heat. Season with salt and pepper to taste.

3: Preheat the oven to 200°C/Fan 180°C/Gas 6. Bring a large pan of salted water to the boil. Add the macaroni and cook for 8–10 minutes or until al dente.

4: In the meantime, to cook the mushrooms, melt the butter with the olive oil in a frying pan over a high heat. Add the mushrooms and cook, stirring occasionally, for 10 minutes. Add the garlic and thyme leaves and cook for another 2–3 minutes.

5: Drain the macaroni, keeping back some of the cooking water. Mix the macaroni with the cheese sauce and cooked mushrooms. If the mixture is too thick, loosen it with a little of the reserved cooking water. Season with salt and pepper to taste.

6: Spoon into a large oven dish, about 35 x 25cm and 8cm deep. Sprinkle the breadcrumbs and Parmesan evenly over the surface then bake on the middle shelf of the oven for 10 minutes. Turn the grill on and cook for a further 5 minutes until golden brown, keeping a close eye on the topping to make sure it doesn’t burn.

7: Serve in warmed bowls, sprinkled with chopped parsley and accompanied by a green salad, if you like.