How to Make a Custard?

Heat milk or cream in a saucepan until warm, not boiling

Whisk egg yolks with sugar until smooth and pale

Slowly pour the warm milk into the egg mixture while whisking constantly

Return the mixture to the saucepan

Cook over low heat, stirring constantly, until it thickens enough to coat the back of a spoon

Remove from heat immediately

Strain the custard through a fine sieve if needed

Stir in vanilla or other flavoring if desired

Cool the custard before serving or using in a recipe