Here is the original recipe from Skinny Taste with my changes in pink:
Cook noodles in a pot of salted water according to package directions, I like to under-cook them a bit so I can mix it with the sauce and let it finish cooking.
Meanwhile, while the water starts to boil for the noodles, heat a large nonstick skillet over medium-high heat. Melt butter over medium heat and add onions to the pan. Cook 2 - 3 minutes over medium-low heat.
Add flour; stir with a wooden spoon for 30 seconds. Gradually add broth, Worcestershire sauce, and tomato paste, stirring constantly. Add mushrooms, thyme, salt and pepper; stir and cook 4-5 minutes or until thickened and bubbly, stirring constantly.
Add wine; bring to a boil, reduce heat, and simmer 4 minutes. Remove from heat; let stand 30 seconds. Stir in sour cream; add noodles, mix well and garnish with parsley if desired.