Place a large pot of water over high heat. When water comes to a boil add a teaspoon of salt and add noodles. Cook noodles until tender. Follow directions on the package.
When noodles are tender, drain and set aside. Keep warm.
While the noodles are cooking, cook ground beef and onion over medium heat in a large skillet.
Break up beef into crumbles as it cooks.
Add minced garlic and cook for another 1-2 minutes.
Remove beef mixture from the skillet and drain off any excess fat. Set beef mixture aside and keep warm.
In the same skillet heat butter over medium heat.
Once butter is melted, sprinkle flour over the butter.
Use a whisk to combine butter and flour. Continue to stir continuously until flour begins to turn a light toasted brown in color.
Slowly add beef broth and Worcestershire sauce to the pan, whisking continuously until mixture is smooth and no lumps remain.
Continue whisking sauce as it comes to a simmer and starts to thicken.
Whisk in the Cream of Mushroom soup, whisking until well combined.
Add salt and pepper.
Whisk in the sour cream and continue to stir until sauce is smooth and creamy.
Return beef to the pan and stir to combine.
Continue to cook over medium heat until sauce and beef are heated through and sauce is rich and thick and creamy.
Spoon a generous amount of the beef sauce over a bed of noodles.
Garnish with freshly chopped parsley to serve.
Notes
VARIATION: Add a 6.5 oz can of sliced mushrooms (drained) to the sauce.