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 won’t stick together. Cover loosely to keep warm.