Bean sprouts are best known from the cooking of China, where mung bean sprouts became popular in the south and soybean sprouts in the north about 1,000 years ago. Many other legumes are sprouted in Asia and elsewhere, from the tiny alfalfa seed to the massive fava bean. Cooks sometimes trim larger sprouts of their rootlets, primordial leaves, and dense cotyledons, so that the subtle texture and flavor of the stems can be enjoyed without distraction. Sprouts are generally cooked minimally if at all to preserve the delicate flavor and tender but crunchy texture.