Mix the cornflour and water in a small saucepan. Add the milk, peanut butter and sugar, to taste. Cook, stirring with a whisk, over moderate heat until thickened and thoroughly mixed. Cool and refrigerate. Serve in tumblers, with or without ice.
Though this is traditionally served as a soft drink, many Trinidadians find it improved, as indeed I do, by the addition of a good Trinidadian