Mook is a traditional Korean food made from mung beans, cowpeas, buckwheat, or acorns, which takes the form of a smooth starch gel. The starch is extracted with water, boiled until it thickens, then cooled until it sets into a firm, sliceable jelly. Served chilled and sliced with seasoned soy sauce, vinegar, and vegetables, it is prized for a clean taste and slippery, refreshing texture. As a starch gel it is low in fat and highly perishable once cut, requiring refrigeration and quick consumption. Acorn versions carry a characteristic slight bitterness from tannins that soaking and processing reduce.