Cook the Pasta: Start by boiling your pasta in salted water according to package instructions. Reserve about 1 cup of pasta water before draining in case you need it to adjust the sauce later.
Add Onions: Toss onions & chopped garlic. Cook them until they get golden.
Sauté the Mushrooms: Add mushrooms and cook for 8-10 minutes until they’re golden and have released their moisture.
Make It Creamy: Lower the heat and put heavy cream along with milk for a creamy texture. Let the sauce simmer gently until it thickens, for about 3-4 minutes. If it gets too thick, use the saved pasta water to thin it out to your liking.
Combine: Add the cooked pasta to the pan and roll the sauce and pasta, such that sauce evenly coats the pasta. Season with salt and pepper to taste.
Serve: Top it off with extra crispy butter mushrooms and garnish with parsley or thyme, and serve immediately.
Notes
Don’t Rush the Mushrooms: Make sure to give the mushrooms enough time to brown properly. This caramelization is where much of the flavor comes from.
Save That Pasta Water: The starchy water is perfect for adjusting the consistency of your sauce, so don’t forget to reserve some before draining the pasta.
Season well: Taste and season your sauce throughout the process to make sure it’s balanced and flavorful.