If you happen to have any leftover creme brulee mixture, pour it into a baking dish and put it into another roasting pan. Add hot water about halfway up the sides of the dish and bake until custard is starting to set, yet still a little wiggly in the middle, about 35 to 45 minutes. Remove and cool to room temperature. Cover and refrigerate overnight or at least 6 hours. Refer to recipe for caramelizing sugar on top after it has cooled completely.