Choi sum (also spelt choy sum), is an Asian leaf vegetable very widely used in Chinese traditional cooking. The botanical name of the plant variety is ‘Brassica rapa parachinensis’. Alternatively called ‘Chinese flowering cabbage’, choi sum can be used in all Chinese traditional ways of cooking, especially stir-fries, blanched dishes and in broths. The name choi sum can be literally translated as ‘vegetable heart’.