This simmered rice pudding, with a whisper of citrus as a high note, is from Sandy Gluck, a chef and dear friend. Sandy’s cooking is distinguished by its full, true flavor, and this rice pudding is no exception. The caramel sauce, made with a base of fresh citrus juice instead of water, is optional, but it’s a delicious touch. Any leftover sauce can be kept refrigerated for a month; serve it warm, over ice cream.