Custard is a range of preparations based on milk and eggs. Most commonly, custard refers to a dessert or dessert sauce, but custard bases are also used for quiches and other savoury foods. As a dessert, it is made from a combination of milk or cream, egg yolks, sugar, and vanilla. Sometimes flour, corn starch, or gelatin are also added.
Custard is usually cooked in a microwave, double boiler (bain-marie) or heated very gently in a saucepan on a stove, though custard can also be steamed, baked in the oven with or without a hot water bath, or even cooked in a pressure cooker. Cooking until it is set without cooking it so much that it curdles is a delicate operation, because only 5–10 °F (3–6 °C) separate the two. A water bath slows heat transfer and makes it easier to remove the custard from the oven before it curdles.
Depending on how much egg or thickener is used, custard may vary in consistency from a thin pouring sauce (crème anglaise), to a thick blancmange like that used for vanilla slice or the pastry cream used to fill éclairs.
Custard is an important part of dessert recipes from many countries.