Cook egg noodles according to package directions. Drain and set aside.
In a large skillet over medium-high heat, brown ground beef, breaking it up with a spoon, about 5-7 minutes. Drain excess fat if needed.
Add diced onion and mushrooms to the beef and cook until softened, about 5 minutes. Add garlic and cook for 1 minute more until fragrant.
Sprinkle flour over the beef mixture and stir well to coat everything evenly. Cook for 1-2 minutes.
Slowly pour in beef broth and Worcestershire sauce, stirring constantly. Bring to a simmer and cook until sauce thickens, about 3-4 minutes.
Remove from heat and stir in sour cream, salt, and pepper until smooth and creamy.
Serve the stroganoff over cooked egg noodles and garnish with fresh parsley if desired.