Preheat oven to 190 degrees C. Lightly grease a baking dish.
Butter one side of every piece of bread, then cut slices into triangles. Place half of the bread buttered side up covering the base of the baking dish. Sprinkle sultanas and sugar onto bread, then place the remaining bread on top buttered side up.
In a saucepan over medium heat, warm milk until nearly boiling. Remove from heat and combine with eggs, stirring vigorously. Pour the mixture over the bread and allow to soak for ten minutes. Grate nutmeg over the top.
Bake in the middle of the oven for 45 minutes until set and lightly browned.