KO EN Thai Side dish⏱ 25 minEdit history

Pad Pak Boong Fai Daeng (Fire-Charred Morning Glory Stir-Fry)

Name: Pad Pak Boong Fai Daeng (Fire-Charred Morning Glory Stir-Fry)
Prep time: 20 min
Cook time: 5 min
Total time: 25 min
Yield: 3 servings
Cuisine: Thai
Ingredients: 400 g water spinach; 5 cloves garlic; 3 Thai bird's eye chillies; 2 tbsp neutral oil; 1 tbsp tao jiao; 1 tbsp oyster sauce; 1 tsp fish sauce; 1 tsp sugar; 1 tbsp water

Water spinach thrown into a wok hot enough to smoke and finished inside a minute. "Fai daeng" means red fire, and that is the whole recipe: heat. The stems are hollow, so how thoroughly you dried them is what decides whether this sears or steams.

Ingredients

3servings

Serves 2-3 (4 as a side)
water spinach · morning glory, kangkung, ong choy; trim off the woody base400 g
garlic · crushed roughly under a blade — not finely minced5 cloves
Thai bird's eye chillies · prik kee noo, bruised together with the garlic3
neutral oil · high smoke point; not sesame or olive oil2 tbsp
Sauce — mixed in advance
tao jiao · Thai fermented yellow soybean paste; half a tbsp of doenjang plus half a tbsp of water instead1 tbsp
oyster sauce1 tbsp
fish sauce1 tsp
sugar1 tsp
water · just enough that the sauce does not dry the instant it hits the wok1 tbsp

Steps

Wash the water spinach, cut the woody base off and cut it into 5-7cm lengths. Keep the stems and leaves in separate piles — the stems need a few seconds longer.
Dry it completely. Spread it in a colander and press it with kitchen paper over 10 minutes. Water spinach stems are hollow and trap water inside, which makes this step matter far more than it does for other greens. Put it in wet and you are steaming, not stir-frying.
⏲ 10 min
Bruise the garlic and chillies roughly in a mortar. Finely minced, they burn to bitterness within seconds at this temperature.
Mix the sauce in a small bowl now. The cooking takes a minute, so doing this at the stove is already too late.
Put the wok — or your largest cast-iron pan — over the highest heat for 2-3 minutes, until it begins to smoke. Oil added to it should shimmer immediately.
⏲ 3 min
Add the oil, then the garlic and chillies for 10 seconds only. The moment you smell them, move on; if they have coloured, you are already late.
⏲ 10 sec
Stems first, for 30 seconds. Toss the wok rather than stirring — stirring alone drops the temperature and the greens start weeping.
⏲ 30 sec
Add the leaves and pour the sauce around the rim of the wok, not into the middle, which would kill the heat. Within 40 seconds the leaves collapse and the sauce coats everything. Done.
⏲ 40 sec
Off the heat and onto a plate immediately. Left in the wok it keeps cooking in the residual heat, turns khaki and floods. A little liquid pooling on the plate is normal.

Tips & Variations

Variations

Stir-fried water spinach has a different name and a different sauce in every country. The vegetable itself is common across Southeast Asia and southern China and belongs to no one country. This page covers the version that has a name of its own in Thailand.
Kangkung belacan (Malaysia, Singapore): fried with belacan, fermented shrimp paste, and sambal. Much saltier and heavier.
Tumis kangkung (Indonesia): shallots, garlic and chilli, with a little kecap manis.
Chao kong xin cai (炒空心菜) (southern China): garlic and salt only, or fu yu (fermented bean curd). The most pared-back of them.
Rau muống xào tỏi (Vietnam): garlic oil, with lime squeezed over.
Adobong kangkong (Philippines): braised down in soy sauce and vinegar.
Without tao jiao: half a tablespoon of doenjang loosened in water. Doenjang is nuttier and saltier, so cut the fish sauce back. Doubanjiang makes it hot and red — a different dish (fermented pastes).
With meat: fry pork or prawns first, lift them out, cook the greens, and combine at the end. Cooked together, the greens collapse while the meat is still going.
Different greens: the closest substitutes are choy sum stems or pak choi. Spinach has no real stem and folds in thirty seconds, so it does not belong in this method — blanching, as in sigeumchi-namul, is the right treatment for it.
Thai stir-fries on the same logic: pad kra pao and pad see ew are also decided by wok temperature, and khao pad applies it to rice. On the Chinese side, chow mein and tomato and egg solve the same problem in the same short window.

Tips

The hollow stem is the technical heart of this dish. Water spinach — 空心菜, "hollow-heart vegetable" — has stems that are tubes, and washing water sits inside them. Shake the outside dry and put it in the wok and that trapped water bursts out, drops the temperature, and turns the stir-fry into a steam. The ten minutes of draining is not an optional step.
Heat the wok until it smokes. A domestic burner has less than half the output of a restaurant's, so preheating and not overloading are the only compensations available. If 400g will not fit, cook it in two batches. Cramming the wok is the single most common cause of failure (heat control, dry heat and moist heat).
Pour the sauce around the rim. It reduces on contact with the hot metal and the aroma comes up. Poured over the food in the middle it only drops the temperature and stays a liquid.
Bruise the garlic, do not mince it. Finely minced garlic has too much surface area and burns in seconds at this heat. Bruised, the aroma comes out and the burning comes late (browning).
Choose the oil by smoke point. At the temperature the wok has to reach, sesame oil and extra virgin olive oil scorch first and leave bitterness. Aromatic oils go in after the heat is off (cooking oils).
Season with fermented pastes, not salt. Tao jiao, oyster sauce and fish sauce bring savouriness along with the salt. Salt alone tastes flat, and the teaspoon of sugar is there to round off the edge of the fish sauce (building umami, balancing flavour).
Whole chillies are fine too. Bruised, the heat spreads through the dish; halved, they can be picked out. Deseeding cuts the heat and keeps the aroma (chilli and heat).
Past a minute it is a different dish. The moment the leaves collapse it is finished; after that the colour drains and water comes out. Unlike dishes where blanching preserves the colour, here it is brief, very high heat that does it (blanching vegetables).
Have the plate ready. In the wok it keeps cooking on residual heat. Turning off the burner and moving it out should be one motion (serving temperature).
Best not to have leftovers. Cold, it loses the colour and the crunch together, and reheating brings back neither. Cook less and finish it at the table.