Bring a large pot of salted water to a boil and cook pasta according to package directions until al dente.
While pasta cooks, heat olive oil in a large skillet over medium-high heat.
Add sliced mushrooms to the skillet and sauté for 5 to 7 minutes until browned and moisture has evaporated.
Reduce heat to medium and add butter and minced garlic to the mushrooms.
Cook for 1 to 2 minutes until garlic is fragrant, taking care not to burn it.
Reserve 1/2 cup of pasta water, then drain the pasta.
Add the cooked pasta, reserved water, and Parmesan cheese to the skillet.
Toss continuously until a light sauce coats the pasta.
Season with salt and pepper, garnish with fresh parsley, and serve immediately.