Mushroom Croustades are a one-bite, timeless, crowd-pleasing appetizer that can be made ahead - perfect for entertaining! Finely chopped mushrooms and onion are sautéed in butter, thickened with flour and seasoned with cream, wine, green onion, parsley and cayenne pepper. After resting, the mixture is spooned into small toasted bread cups, topped with Parmesan cheese and baked. Can be frozen for up to 3 months, too!
Make ahead: Croustade shells can be placed in a Ziploc baggie and frozen for up to 3 months. Filling can be stored in the refrigerator for up to 1 day. Alternatively, croustades can be filled, sprinkled with Parmesan cheese, placed on a cookie sheet and placed in the freezer. Once frozen, place in a ziptop baggie. To heat, place frozen croustades on cookie sheet and increase cooking time by 3 to 5 minutes.