Bring a large pot of salted water to a boil.

In a skillet, heat the olive oil over medium heat and add the diced onion. Sauté until translucent, about 3-4 minutes.

Add the sliced mushrooms to the skillet and cook until softened, around 5-7 minutes.

Stir in the minced garlic and cook for an additional minute.

Lower the heat and add the heavy cream to the skillet. Let it simmer gently, stirring occasionally.

Stir in the grated Parmesan cheese until melted and well combined.

Once the pasta is cooked and drained, add it to the sauce and toss until evenly coated.

Season with salt and pepper to taste, and garnish with fresh parsley before serving.