Cook egg noodles according to package directions. Remove from heat, and cover to keep warm.
Heat olive oil and 1 Tbsp. butter in a large skillet over medium-high heat. Add mushrooms, and cook 5 minutes. Stir in garlic and next 4 ingredients, and cook, stirring occasionally, 3 minutes or until mushrooms are slightly browned.
Add flour and remaining butter, and cook, stirring constantly, 2 minutes. Whisk in broth, and bring to boil, whisking constantly; boil, whisking constantly, 5 minutes. Remove from heat. Stir in sour cream and parsley, and serve over noodles.