Mix a little of the milk with custard powder and sugar in a mixing bowl until it forms a paste.
In a saucepan over a high heat, bring the remaining milk nearly to the boil. Watch that it does not boil over! Pour the hot milk over the custard powder mixture, whisking all the time. Return the mixture to the saucepan and place over a high heat, whisking constantly until thickened. Remove from the heat and serve immediately by itself in warmed bowls or over your favourite pudding.
Serve the custard with fruit, like chopped banana or berries or use the custard to make mini trifles.