Here's a rarity for you, which I found this morning. Brassica juncea var gemminfera. 儿菜 (ér cài) or 拳头菜 (quán tóu cài; literally 'fist vegetable)', this is a member of the mustard family found mainly in Yunnan and Sichuan provinces.
It can be boiled, stir fried or roasted and tastes similar to Brussels sprouts. For me this a good thing!