Begin by cooking the egg noodles according to the package instructions. Drain and set aside.
In a large skillet, heat the olive oil over medium heat. Add the chopped onion and sauté until translucent, about 3 minutes.
Add the minced garlic and sliced mushrooms to the skillet. Cook until the mushrooms are softened, about 5 minutes.
Push the vegetables to the side of the skillet and add the ground beef. Cook, breaking it apart with a spoon, until browned and fully cooked, about 5-7 minutes.
Sprinkle the flour over the meat and vegetable mixture, and stir well to combine. Cook for an additional minute.
Gradually add the beef broth, Worcestershire sauce, and Dijon mustard, stirring constantly. Bring the mixture to a simmer.
Reduce the heat to low and stir in the sour cream. Cook until heated through, but do not boil. Season with salt and pepper to taste.
Serve the stroganoff over the cooked egg noodles and garnish with chopped parsley.