Step 1: Cook the Fettuccine : Bring a large pot of salted water to a boil. Cook fettuccine according to package instructions until al dente. Drain and set aside, reserving ½ cup of pasta water.

Step 2: Sauté the Mushrooms : In a large skillet, heat butter and olive oil over medium heat. Add sliced mushrooms and cook 5–7 minutes until browned and tender. Add minced garlic and sauté for 1 minute until fragrant.

Step 3: Make the Alfredo Sauce : Pour heavy cream into the skillet with mushrooms and bring to a gentle simmer. Reduce heat and stir in Parmesan cheese until melted and smooth. Season with salt, pepper, and nutmeg (if using). If the sauce is too thick, add a little reserved pasta water to reach desired consistency.

Step 4: Combine Pasta and Sauce : Add cooked fettuccine to the skillet. Toss until pasta is fully coated with the creamy mushroom sauce. Cook for 1–2 minutes, allowing the flavors to meld.

Step 5: Garnish and Serve : Sprinkle chopped parsley over the top. Serve immediately with extra Parmesan cheese if desired.