Get your prep done before you start cooking: set a large pot with salted water over high heat and bring to a boil. Grate the Parmesan cheese, mince the garlic cloves, chop the mushrooms, and chop the parsley.

Add the pasta to the pot with boiling water and cook until al dente. Drain when ready, reserving 1 cup of cooking water.

Heat a large nonstick skillet over high heat. Once hot, place the mushrooms in a single layer and cook for 1 minute. Stir and continue cooking until they release their moisture, then add olive oil and cook until the mushrooms are golden brown.

Add salt, pepper, thyme, dried onion, and balsamic vinegar. Stir in garlic and cook for 2 minutes. Pour in cream and bring to a simmer. Reduce heat to low and stir in Parmesan. Add parsley and butter, stirring until the butter is fully melted. Simmer for 1 minute to thicken the sauce.

Toss the mushroom sauce with the pasta and 1/4 cup of cooking water. Taste and adjust salt as needed. Finish with freshly ground black pepper and parsley, adding more cooking water if needed. Serve immediately.