Boil a large pot of salted water and cook the egg noodles according to package instructions for about 7-9 minutes until al dente. Drain and set aside.

In a skillet, heat olive oil over medium-high heat. Add ground beef, season with salt and pepper, and cook until browned, about 5-7 minutes. Drain excess fat.

In the same skillet, lower heat to medium and melt butter. Sauté sliced onions until soft, then add mushrooms and cook until golden brown.

Add minced garlic and cook for another minute. Sprinkle flour over the mixture, stirring to blend.

Gradually pour in beef broth while stirring. Bring to a simmer and cook for 3-4 minutes.

Return browned beef to the skillet, then mix in cream cheese, sour cream, and mustard. Stir until creamy.

Add drained egg noodles to the skillet and toss with the sauce for about 1 minute.

Let the mixture sit off heat for a minute to thicken, garnish with parsley, and serve hot.