Preheat oven to 350 degrees.
Place beef in a large skillet.
Season beef with salt and pepper.
Brown the beef over medium high heat for 8 minutes, break up the meat.
Remove beef from skillet and set aside.
Heat oil in the same skillet.
Add mushrooms, onions and garlic.
Cook about 2 minutes or until the onion is tender.
Reduce heat to medium low and simmer for three minutes.
Remove from heat, stir in soup, sour cream and mustard until well blended.
Return beef to the skillet, stir to blend.
Spray a 13X9 inch baking dish with regular PAM.
Place noodles in the prepared baking dish.
Pour the beef mixture over the noodles.
Stir mixture until all the noodles are coated.
Bake for 30 minutes - heated all the way through.
Sprinkle with chopped parsley before serving.