Take a medium-sized ovenproof dish and grease it well with butter. Cover the bottom with a layer of buttered bread. Sprinkle with chopped dates. Repeat the process ending with a layer of bread. Beat the egg well and add milk and essence.
Pour over the bread and leave to soak for about an hour.
Sprinkle with nutmeg and bake in a moderate oven for about an hour or until nicely browned on top.