12 ounces pasta (fettuccine, linguine, or pappardelle)
2 tablespoons olive oil
2 medium leeks (white and light green parts only), thinly sliced and rinsed
8 ounces cremini mushrooms, sliced
3 cloves garlic, minced
1/2 cup dry white wine (or vegetable broth)
1/2 cup heavy cream
1 cup freshly shredded Gruyere cheese
1/4 teaspoon freshly ground black pepper
Salt, to taste
1/4 cup chopped fresh parsley (optional, for garnish)
Instructions
Cook pasta in generously salted boiling water according to package directions until al dente, 8-10 minutes. Reserve 1/2 cup pasta water before draining.
Heat olive oil in a large 12-inch skillet over medium heat until shimmering.
Add sliced leeks and cook for 6-8 minutes, stirring occasionally, until soft and golden brown at the edges.
Stir in mushrooms and cook for 5-7 minutes, stirring occasionally, until tender and beginning to brown.
Add minced garlic and sauté for 1 minute, stirring constantly, until fragrant.
Pour in white wine and stir, scraping up browned bits from bottom. Simmer for 2 minutes until reduced by half.
Stir in heavy cream and reduce heat to low. Simmer gently for 3-4 minutes until slightly thickened.
Remove from heat. Add Gruyere cheese in three additions, stirring after each until completely melted. Season with salt and pepper to taste.
Add drained pasta to skillet and toss to coat. Add reserved pasta water 2 tablespoons at a time if sauce is too thick.
Sprinkle with fresh parsley if desired and serve immediately in warm bowls.
Notes
Slice and rinse leeks thoroughly in cold water to remove trapped sand between layers.
Grate Gruyere cheese fresh for smoothest melting. Pre-shredded cheese can make sauce grainy.
Can substitute Comte, aged Swiss, fontina, or white cheddar for Gruyere.
Add grilled chicken, shrimp, or crispy pancetta for extra protein.
Sauce thickens when cooling. Reheat gently with splash of water or cream.