Chye Sim / Choy Sum

Also known asChoy Sum · Choi Sum · Caixin · Cai Xin · Chinese Flowering Cabbage · Brassica rapa var. parachinensis · 菜心

Name: Chye sim or choy sum (Brassica rapa var. parachinensis) — a Cantonese leafy vegetable with bright green leaves, tender stems and small yellow flowers. The name means “vegetable heart.” It is often sold as flowering Chinese cabbage.

Description

Choy sum is native to southern China, and is one of the most common vegetables in Cantonese cooking and in Southeast Asian cuisines such as those of Malaysia, Singapore and Thailand, where it goes by chye sim. It is harvested young, usually when the first flower buds appear, and the flowers are edible too.

The stems are crisp and sweet, and the leaves are tender with a mild mustardy note, with less bitterness than gai lan. It cooks in 2 to 3 minutes and is often served simply with oyster sauce.

Main nutrition value

Choy sum provides vitamin K, vitamin C, vitamin A, folate and calcium, for very few calories.

How best to be consumed

Choy sum is cooked quickly and simply.

1. Blanch or steam whole, then drizzle with oyster sauce and hot oil.
2. Stir-fry with garlic and ginger, or with tofu or mushrooms.
3. Add to noodle soups, congee and hot pots.
4. Eat the flowers and young stems too.
5. Wash well, and cut in pieces so the stems and leaves cook evenly.

Overconsumption could cause…

Choy sum is safe and healthy in food amounts.

1. Possible effects on warfarin and similar blood-thinning medicines because of the high vitamin K content, so keep intake steady rather than avoiding them.
2. Bloating and gas from the fibre and fermentable carbohydrates in brassica greens.
3. Possible effects on thyroid function in people with an underactive thyroid or iodine deficiency if very large amounts are eaten raw, since brassicas contain goitrogens; normal cooked servings are fine.
4. A lot of salt and sodium if served with plenty of oyster sauce.

GroupsLeafy Green VegetablesCruciferous (cabbage family)ChineseFresh

Related foodsBaby Bok ChoyBok Choy / Pak ChoyGai Lan / Chinese BroccoliNapa Cabbage / Chinese CabbageTatsoiCollard Greens

Wikipedia — Choy sum, used for origin, naming and history: https://en.wikipedia.org/wiki/Choy_sum