These smallish red beans are relatively new to our shores and public perception, for what it is, probably imagines them alongside mung beans and dairy-free chocolate on the health store shelves. But in their east Asian homelands they enjoy huge popularity and are often eaten in a sweetened form, such as the red bean paste used in versions of dim sum. To cook the dried variety, soak overnight then bring to the boil and simmer for 30 minutes until tender. You can also find them in tins at the supermarket. Red kidney or haricot beans can be substituted. Also known as azuki and adzuki beans.