Prepare the morning glory by thoroughly washing the stems and leaves under cold running water. Cut the stems into 3-inch lengths, discarding any tough bottom ends, and keep them separate from the delicate leafy tops.

Heat the vegetable oil in a large wok or deep skillet over medium-high heat until it begins to shimmer. Add the minced garlic and sliced red chilies, stirring constantly for about 30 seconds until the garlic is fragrant and lightly golden.

Add the sliced pork to the wok, spreading it out in a single layer to sear. Cook for 3 to 4 minutes, stirring occasionally, until the pork is cooked through and begins to brown at the edges.

Stir in the fermented yellow soybeans, oyster sauce, and sugar, coating the pork evenly. Let the mixture bubble for about 1 minute to caramelize slightly and release its deep, savory aroma.

Toss in the morning glory stems first, tossing for 1 minute, then add the leaves and the water to create steam. Crank the heat to high and stir-fry vigorously for 2 minutes until the greens are wilted but still vibrant green and crisp.

Transfer the stir-fry immediately to a serving platter to prevent the morning glory from overcooking and losing its crunch. Serve hot as a main or side dish with plenty of steamed jasmine rice.