In a large skillet, heat the olive oil over medium-high heat. Add the sliced beef and cook until browned, about 3-4 minutes. Remove the beef from the skillet and set aside.
In the same skillet, add the chopped onion and cook until translucent, about 3 minutes. Add the minced garlic and sliced mushrooms, cooking until the mushrooms are tender, about 5 minutes.
Return the beef to the skillet. Pour in the beef broth, Worcestershire sauce, and Dijon mustard. Stir to combine and bring to a simmer. Let it cook for about 5 minutes to allow the flavors to meld.
Reduce the heat to low and stir in the sour cream. Cook until heated through, about 2-3 minutes. Season with salt and pepper to taste.
Meanwhile, cook the egg noodles according to package instructions. Drain and set aside.
Serve the beef stroganoff over the egg noodles and garnish with chopped parsley.