Preheat oven to 400°. In medium size bowl, whisk egg and milk together. Set aside. In another medium sized bowl, combine all chicken ingredients. Pat each chicken breast dry with paper towels. Coat each breast with egg mixture and then with parmesan flour mixture. Bake for about 20-30 mins or until no longer pink in center.

While chicken is cooking, melt butter for 1 minute on medium heat. Add minced garlic, simmer for 1 min. Add flour til paste like. Add chicken broth. Stir. Add sour cream. Stir. Add parmesan cheese and seasonings. Add broth if too thick.

Saute up 1 large onion and about 6 mushrooms in butter to place on top of chicken.