1. Combine Group I ingredients in suitable cooking container, cover, and cook for 10 minutes at a gentle boil. 2. Saute onions with butter in Group II, add mushrooms and Group I ingredients. 3. Combine Group III ingredients, then add Group I and Group II ingredients. 4. Prepare 3/4 cup rice or noodles. 5. Heat combined Group I, II, and III to serving temperature and add sour cream. 6. Serve stroganoff with rice or noodles.