Slice off the tough ends, and cut kailan in halves, lengthwise. Wash thoroughly in a few changes of water to remove soil particles and grit. (If using other varieties of kailan, please read Recipe Notes below). Drain off excess water and set aside.
In a small bowl, combine sauce ingredients and stir to mix well. Do a taste test, and tweak ingredient amounts to suit your tastes. In a separate bowl, combine corn flour and water.
Heat up a wok over medium heat. When wok is hot, reduce to low heat, add cooking oil. Tip in the minced garlic and stir continuously until garlic just starts to turn a light, golden brown. Turn off the heat and remove garlic immediately with a slotted spoon (note: garlic burns quickly once it turns golden brown, and will taste bitter). Leave the garlic-infused oil in the wok.
Heat up the wok (with garlic-infused oil) over high heat. When hot again, tip in the vegetables all at once and stir fry vigorously for 1 minute, or until stems and leaves just start to soften and turn limp.
Add the sauce, and thicken with corn starch solution to desired consistency (remember to stir the cornstarch solution vigorously before adding in). Dish out onto serving plate, garnish with fried garlic bits, and serve immediately.