Cooking tip: To make a flavourful slaw, toss shredded napa cabbage and grated carrots with a bit of sesame oil, soy sauce, chili flakes and rice vinegar. Sprinkle with toasted sesame seeds.

Nutrition note: It contains heaps of vitamin K, which is essential for proper blood clotting.

Perfect pick: Choose ones that seem heavy for their size, with fresh unblemished leaves.