Cook the Pasta:
Bring a large pot of salted water to a boil. Cook the pasta according to package directions until al dente. Reserve about a cup of the starchy pasta water before draining.

Sauté the Mushrooms:
While the pasta cooks, heat the butter and olive oil in a large skillet over medium-high heat. Add the mushrooms and cook for about 5 minutes, stirring often, until they are well-browned. Add the minced garlic and cook for another minute until fragrant.

Build Your Elegant Sauce:
Deglaze the pan with the dry white wine, scraping up any browned bits from the bottom. Simmer until the wine has mostly evaporated. Stir in the Italian seasoning, lemon juice, flour, and Dijon mustard until a smooth paste forms.

Finish and Combine:
Slowly stir in the heavy cream and simmer for a couple of minutes until the sauce begins to thicken. Season with salt and pepper. Add the cooked pasta to the skillet and toss to coat, adding a splash of reserved pasta water if needed to create a silky consistency. Serve immediately, topped with fresh parsley and parmesan cheese.