Make Quick Belacan Sauce (skip if you’ve already made it in advance):
If you haven’t made our belacan sauce in advance, follow these directions to make a quick version.
Chop the soaked dried shrimp, and add it to a mortar and pestle along with the ¼ cup of water it soaked in. Also add the belacan, sliced shallot, garlic, dried chili, and holland chili. Mix and grind until well-combined. The belacan should dissolve into the other ingredients and be well-incorporated. Set aside for 15 minutes.
Add 1 ½ tablespoons oil to a wok or saucepan over medium heat, and add the sauce mixture. Fry for about 5-8 minutes, or until fragrant, stirring occasionally and adjusting the heat as necessary so it doesn’t burn. Set aside.
Trim and Wash the Water Spinach (Kangkung)
Trim the 1-2 inches from the tough ends of the water spinach and discard. Pick out and discard any leaves that aren’t fresh and vibrant green.
Cut the remaining water spinach into 2 to 3 inch (5-8 cm) lengths. Transfer them to a large basin of cold water. They should be fully submerged to clean them properly. Use your hands to agitate the water and the vegetables to shake out any grit. Soak for 5 to 10 minutes to allow any dirt or sand particles to settle.
Gently lift the water spinach out of the water to a colander. Discard the sandy water, and repeat the process 1-2 times, until the vegetables are clean.
Drain completely, giving the colander a few good shakes to remove excess water. You can also run the clean water spinach through a salad spinner to make sure it’s really dry.
Prepare Other Ingredients in Advance
Prepare and measure out the julienned ginger, chopped garlic, Shaoxing wine, sugar, MSG, and white pepper.
Cook!
Heat your wok over medium high heat until it begins to smoke. Immediately add 3 tablespoons of oil, along with the ginger and garlic. Stir for 5-10 seconds, and add the belacan sauce. Cook for another 10 seconds, and add the water spinach.
Immediately turn your heat up to the highest setting, and use a scooping motion to mix the vegetables, oil, and sauce together. When the vegetables are half wilted, gather them together in a pile in the center of the wok.
Pour the Shaoxing wine around the perimeter of the wok, and cover it. This will allow the sides of the wok to heat up, while the vegetables are protected from burning by the liquid pooled in the center. It’s a classic Cantonese technique, and can help you achieve a wok hei seared flavor even if you don’t have a large burner.
Depending on how hot your stove is, wait 30-60 seconds before removing the cover. Toss in the sugar, MSG, and white pepper.
Spread the vegetables out onto the sides of the wok, and mix in a circular motion to get them seared on the heated wok perimeter.
Gather the vegetables to the middle again, let the wok heat up for 30 seconds (uncovered), and repeat the process. Taste and add salt if needed. Serve immediately.