In a large nonstick fry pan, melt butter over high heat.  Place flour in pie pan; add chicken and turn to coat well.  Place chicken in fry pan and cook, turning about 5 minutes to brown well on both sides.  Stir in onion, mushrooms and any remaining flour. Reduce heat to medium and cook, stirring, until onion is golden brown, about 5 minutes.

In a small bowl, whisk together chicken broth and mustard. Pour mixture into fry pan and stir. Bring to a boil; reduce heat and simmer about 5 minutes. Stir in sour cream and parsley; simmer for 2 additional minutes. Season with salt and pepper to taste.

Serve over egg noodles.

Serves 4.

Freezer Instructions:
Transfer stroganoff to plastic container with tight fitting lid. Let cool, uncovered, for 20 minutes.  Refrigerate, uncovered, until cold, about 30 minutes.  Cover tightly and freeze until needed.  To thaw, transfer from freezer to refrigerator 12-24 hours before needed. Reheat in large, covered fry pan over medium low heat.  Bring to a simmer and cook about 5 minutes.