Gai Lan, which is known as Chinese broccoli, can be found at many Asian grocers. But if you can't find it, don't despair, fresh tender broccoli can be substituted in a pinch (it tastes quite similar anyway). This makes a wonderful light soup which can be totally vegetarian if you wish. It does turn out a bit spicy with the full three peppers sliced in (with the seeds)(I used fresh red Thai dragons in the recipe), so adjust the heat to your own taste. I think this also might be nice with chicken substituted for the tofu- if you choose to do that, add about 10-12 ounces of chopped cooked chicken where you would add the tofu. Enjoy!