Mushroom Gravy

Clean mushrooms and slice. Place in 2 qt casserole with onion and butter. Cover and microwave at high for 2 to 3 minutes. Sprinkle with flour and stir to blend.
Dissolve cornstarch and bouillion granules in water and add gradually to mushroom mixture stirring constantly. Stir in parsley flakes and microwave at high 4-6 minutes or until mixture bubbles and thickens. Gradually blend in milk or half and half. Microwave 3-5 more minutes until thickened.