Tatsoi, also known as spinach mustard or spoon mustard, is a leafy green vegetable that belongs to the Brassica family. It has dark green, spoon-shaped leaves that form a compact rosette shape, and a crisp and tender texture. Tatsoi has a mild, slightly sweet flavor with a hint of mustard-like tanginess. It is commonly used in salads, stir-fries, and soups, and is popular in Asian cuisines. It is a rich source of vitamins A, C, and K, as well as calcium and iron, making it a nutritious addition to a healthy diet.