Choi sum / Choy sum is very popular in Southern China. As a special produce in Guangdong province, this leafy vegetable is sweet and tender. It is rich in vitamin B, C, carotene and dietary fibre, also an excellent source of folic acid. Stir fry with meat slices (optional), garlic and ginger for a crispy texture. Steaming the vegetable will give a sweeter taste and a tender texture.