Heat-resistant choi sum. Similar to Gunsho, choi sum reaches maturity just a few days later. Choi sum is a highly sought-after vegetable in Hong Kong, Taiwan, and China. Its stems boast a vibrant, vivid green color, are exceptionally sweet and tender, and are typically harvested right before or as the first buds begin to open. The stems have the ability to regrow for repeated harvests. They are perfect for stir-frying, steaming, or adding to soups.