If you can’t find adzuki beans, you can substitute dried small red beans. Dried tangerine peel, which lend a distinctive floral-citrus flavor, is usually sold in one whole piece in Asian grocery stores. Online, you can find it both whole and in strips. I used lump sugar, common in various Chinese sweet soups, because it’s slightly less sweet than granulated sugar. You can substitute regular sugar or even brown sugar, which will add a nice caramel note.