Boil a pot of salted water and add your chosen pasta. Cook until al dente (about 8-10 minutes), then drain, reserving a bit of that lovely cooking water for later.

In a large skillet, melt butter over medium heat. Add the sliced leeks and cook until they turn golden and caramelized, around 10 minutes.

Toss in the sliced mushrooms and cook for 5-7 minutes, until tender and nicely browned.

Lower the heat, then stir in the cream and Gruyere. Keep stirring until the cheese melts and the sauce thickens.

Toss the drained pasta into the sauce, ensuring every strand is coated in that rich, cheesy goodness.