In a large skillet, heat olive oil over medium heat. Add the chopped onion and sliced mushrooms, and sauté until the onions are translucent and the mushrooms are tender.

Add the ground beef to the skillet and cook until browned, breaking it apart with a spoon.

Sprinkle flour over the beef mixture and stir to combine. Gradually add beef broth while stirring to avoid lumps.

Bring the mixture to a simmer and let it cook for about 5 minutes until it thickens slightly.

Stir in the sour cream and season with salt and pepper to taste.

In a separate pot, cook the egg noodles according to the package instructions. Drain and add to the beef mixture.

Toss to combine and serve warm.