Begin by bringing a large pot of salted water to a rolling boil. Add 12 ounces of fettuccine or linguine and cook for 8–10 minutes until al dente, stirring occasionally. Once done, reserve ½ cup of the pasta water for later use, then drain the pasta and set it aside while you prepare the sauce.

In a large skillet, melt 2 tablespoons of unsalted butter with 2 tablespoons of olive oil over medium heat. Add the sliced leeks and sauté for 12–15 minutes, stirring frequently, until they become golden brown and caramelized.

Once the leeks are caramelized, stir in 8 ounces of sliced mushrooms into the skillet. Cook for about 6–8 minutes until the mushrooms have softened and released their moisture. Then add 2 cloves of minced garlic to the skillet and sauté for an additional minute.

Lower the heat to medium-low before adding ½ cup of heavy cream to the mushroom-leek mixture. Gradually stir in ¾ cup of shredded Gruyere cheese, mixing until the cheese melts and the sauce becomes creamy.

Introduce the cooked pasta to the skillet, tossing to coat it evenly with the creamy sauce. If the sauce looks too thick, gradually add reserved pasta water until achieving your desired consistency.

Mix in the remaining ¾ cup of Gruyere cheese and season the dish with salt and freshly ground black pepper to taste.

Once everything is well combined, transfer your Creamy Mushroom Gruyere Pasta to warm plates. If desired, sprinkle with freshly chopped parsley for a touch of color and freshness. Serve immediately while hot.