First, mix all the sauce ingredients together and set aside.
Place the sliced pork belly into a cold large pan or wok, then turn the heat to high. Once the pork starts to sizzle, let the fat render out for 4 - 5 minutes until the pieces are golden and cooked through. Use a slotted spoon or spatula to transfer the pork to a plate, leaving the fat in the pan.
Add the onion and garlic to the same pan and stir-fry over high heat for 30 seconds. Toss in the cabbage, kailan and carrot, and stir-fry for another minute.
Pour in the sauce mixture, and add the dried noodles directly into the sauce and use tongs to gently toss and separate the strands as they soften. Cover and cook for 2 - 3 minutes, or until the noodles are tender and have absorbed the sauce.
Return the cooked pork to the pan, add the spring onions, and season with a pinch of black pepper. Toss everything together and serve.
