In a large pot with boiling water, cook the noodles according to package directions.
Add the oil to a large skillet, saucepan, or wok over medium-high heat.
Add the pork belly and stir, cooking for about 10-12 minutes, until the pork belly is crisp. Drain all but 1 teaspoon of the grease from the pan.
While the pork belly is cooking, in a large bowl, whisk together the soy sauce, oyster sauce, sesame oil, and brown sugar. Set aside.
Once the pork belly is nearing your desired level of crispness, add the onions and garlic, stir together, and sauté for about 1 minute.
Add the sauce to the pork belly, onions, and garlic.
Drain the cooked noodles and toss together with the other ingredients in the saucepan until the noodles are well coated.
Garnish with sliced green onions and sesame seeds and serve hot.
Notes
Makes approximately 4-6 servings. Storage: Store in an airtight container in the refrigerator for up to 3 days. Reheat on the stovetop. Noodles: We prefer to use knifecut noodles with this pasta, but you can use almost any noodle that you like!