For the Chicken, place each piece of chicken, boned side up, between two pieces of Saran wrap. Working out from center, pound to form cutlets about 1/4-inch thick. Peel off Saran. Sprinkle with salt. Combine green onion and parsley; sprinkle equal amounts on each cutlet. Place slice of butter on each cutlet; roll as a jelly roll, tucking in ends of meat. Press to seal well. Dust with flour; dip in beaten eggs; roll in bread crumbs. Chill for at least 1 hour. Fry in deep, hot fat (340 degrees) about 5 minutes or until golden brown. Sour Cream Sauce may be served with chicken.
For the Sour Cream Sauce, saute mushrooms in butter. Add sour cream and chives. Heat thoroughly. Pour over, or serve with Chicken Kiev.