Boil a large, salted pot of water for the pasta. Cook 8 ounces uncooked pasta according to package instructions.
Add 1 tablespoon butter and 1 tablespoon olive oil to a skillet over medium-high heat. Add 8 ounces cremini mushrooms sliced and cook for 5-6 minutes or until the mushrooms release their water and it's cooked off. Take the mushrooms out of the pan and set them aside.
Take the pan off the heat. Add 3 cloves garlic minced, ½ teaspoon Dijon mustard, 2 teaspoons all-purpose flour, 2 teaspoons lemon juice, 2 dashes Italian seasoning, and ⅓ cup chicken broth or stock to the pan. Return the pan to the heat. Stir until the mixture is nice and smooth, and let it bubble for a minute or so.
Add in 1 cup heavy cream and let it simmer for 2-3 minutes.
Add ¾ pound medium shrimp and cooked mushrooms to the pan. Cook for 5 minutes or until the shrimp are cooked through and the sauce is thickened to your liking. Taste and season with salt and pepper as needed.
Drain the pasta and toss it with the sauce (add a little pasta water if you wish to thin the sauce). Serve with grated parmesan cheese if desired.
Notes
Anything from 3/4 lb. to 1 lb. of shrimp will work fine.
I used fettuccine pasta - any shape will work for this recipe.