In a large, heavy saucepan, heat the oil over medium heat. Add the onion and mushrooms and cook for about 5 minutes, or until soft. Add the turkey, breaking it up with a spoon, and cook until browned. Add the special seasoning ingredients and stir to thoroughly combine. Stir in the broth, milk and mustard. Bring to a boil over high heat then reduce heat to a simmer and cook, uncovered, for 10 minutes.
While the sauce is simmering, cook the egg noodles in a large pot of salted boiling water for 8-9 minutes, or until al dente. Drain, return noodles to the pan, and toss with the butter so the noodles wont stick together. Cover loosely to keep warm.
Stir the sour cream into the sauce and heat through. Add salt and pepper to taste. Add to the warm buttered egg noodles and toss to coat. Served garnished with parsley.
Twist it up - Making this dish with ground turkey cuts down on cooking time, but you can also use stew meat or flank steak instead. Just be sure to cut the meat into 1-inch cubes, then simmer the sauce for 1 1/2 to 2 hours (instead of 10 minutes). You may have to add a little more milk or water if the sauce gets too thick. When youre ready to eat, just add the sour cream and heat through.