Custard

Warm it gently in a saucepan over a low heat, stirring constantly and scraping the corners. Take it off the heat as soon as it thickens and coats the back of a spoon; boiling can make egg-based custard curdle.

Yes. Mix the powder with a little cold milk until smooth, then stir it into hot milk and sugar. Keep stirring over a medium heat until it thickens; custard powder is usually thickened with cornflour and does not necessarily contain egg.

Reheat it slowly in a saucepan over a low heat, stirring often, or microwave it in short bursts, stirring between each one. Stop when it is steaming hot; if it has thickened in the fridge, whisk in a splash of milk.

Cool leftover custard promptly, cover it and refrigerate it; use it within two days. Reheat only the portion you need, and do not reheat it more than once.

Pour it over fruit crumble, steamed sponge pudding or mince pies, or spoon it into a trifle. Warm custard is especially good with a hot pudding because it softens the sponge and catches in the fruit.

Pouring custard is usually too soft to hold a neat slice in a tart. Use crème pâtissière, which is thickened with egg yolks and often flour or cornflour, or cook custard powder to a much thicker consistency.

Custard is the ready-to-eat sauce or dessert; custard powder is a dry mix, commonly based on cornflour and flavouring, that you cook with milk and usually sugar. Powder alone is not a substitute for prepared custard in a recipe.