In a large skillet, melt the butter over medium-high heat. Once melted, add the beef strips and cook until browned, about 5 minutes. Remove the beef from the skillet and set aside.

In the same skillet, add the chopped onions and minced garlic. Sauté until softened and fragrant, about 3 minutes.

Add the sliced mushrooms to the skillet and cook until they release their moisture and become tender, approximately 4 minutes.

Sprinkle the flour over the beef and vegetable mixture, stirring well to combine. Cook for another minute to remove the raw flour taste.

Gradually pour in the beef broth and Worcestershire sauce, while stirring constantly. Bring the mixture to a simmer.

Once simmering, reduce the heat to low and gently stir in the sour cream, creating a smooth and creamy sauce.

Return the cooked beef to the skillet and season the mixture with salt and pepper to taste, stirring until well combined and heated through.

Serve the Beef Stroganoff hot over cooked egg noodles or rice.