Begin by cleaning and slicing the leeks into thin rounds, ensuring any grit is removed. Rinse the mushrooms and slice them as well, ready to add that earthy flavor.

In a large skillet, melt two tablespoons of butter over medium heat. Add the sliced leeks and sauté for about 7–10 minutes until they become soft and golden brown. Fold in the sliced mushrooms, cooking for an additional 5 minutes until they are tender and browned.

Reduce the heat to low and stir in the heavy cream, followed by the grated Gruyere cheese. Continue cooking while stirring until the cheese melts and the mixture is smooth, about 3–5 minutes.

In a large pot, bring salted water to a rolling boil. Add your choice of pasta and cook according to package instructions until al dente, usually about 8–10 minutes. Reserve ½ cup of the pasta cooking water, then drain the pasta.

Add the drained pasta to the skillet with the caramelized leeks and mushrooms. Toss gently to coat, then gradually add reserved pasta water as needed to achieve your desired sauce consistency.

Plate the pasta into serving bowls, ensuring an even distribution of the sauce. For an extra touch, sprinkle freshly cracked pepper and additional grated Gruyere cheese on top.