Begin by bringing a large pot of salted water to a rolling boil. Add 8 ounces of uncooked fettuccine or linguine, cooking according to the package instructions until al dente, about 8-10 minutes. Once cooked, reserve about a cup of pasta water, then drain and set aside.

In a large skillet, melt 1 tablespoon of butter along with 1/2 tablespoon of olive oil over medium heat. Add 8 ounces of thinly sliced cremini mushrooms and 2 minced garlic cloves. Sauté for 5-7 minutes, until the mushrooms are golden brown and tender.

Transfer the sautéed mushrooms to a plate. In the same skillet, pour in 1/3 cup of dry white wine, scraping up any brown bits. Add 1/4 teaspoon Italian seasoning, 1 teaspoon lemon juice, 1 teaspoon flour, and 1/2 teaspoon Dijon mustard. Whisk until smooth.

Lower the heat slightly and stir in 1 cup of heavy whipping cream into the sauce. Allow it to simmer for 2-3 minutes until it thickens slightly.

Return the sautéed mushrooms to the skillet, stirring them back into the creamy sauce. If the sauce is too thick, gradually mix in some reserved pasta water.

Season the pasta with salt and pepper to taste. Add the drained pasta to the skillet, gently tossing until well-coated in the sauce.

Garnish with chopped fresh parsley and grated Parmesan cheese, if desired. Serve hot.