The excellent description in
One of the most striking foods in the markets, its tubers are so brightly colored—yellow, pink, red, purple, even candy striped—and their waxy skins are so shiny that they seem like botanical jewels or plastic fakes. Many are shaped like small potatoes but others are curiously long and curved like crooked sausages. (One of the bent types, splashed with maroon streaks, is known as ‘Christ’s knee’. A small, pink, curled variety is called ‘shrimp of the earth’.) Their skin is thin and soft and needs no peeling before eating. The white to lemon-yellow flesh has a smooth, silky texture with a nutty taste. Some types are gummy when raw, but in cooking, this characteristic is reduced or lost. Indeed, a major appeal of ulluco is its crisp texture, which remains even when cooked.