Add the pork belly, ginger, garlic, and green onion pieces to a deep pot with a heavy bottom. A Dutch oven works great for this recipe. Add enough water to just cover the pork.
Over high heat, bring the mixture to a boil. Once boiling, allow the pork to cook for exactly 5 minutes.
Remove from heat, strain well and discard everything except the pork. Wipe the pot clean to prepare it for the next step.
Over medium-high heat, add the oil and the drained pork pieces. Cook, turning the pork occasionally, until the pork is browned on all sides. This will take about 7-10 minutes.
Next, reduce the heat to low and add the brown sugar. The sugar will melt and caramelize. Be sure to help it along by stirring the pork around so that every piece is coated with the brown sugar.
Now, add both soy sauces and the rice wine. Stir well and continue stirring for the next five minutes. The liquid will combine with the brown sugar and turn to a glaze.
Finally, add one cup of water and stir well. Cover the pot and simmer for 10 minutes.
If the glaze becomes too thick, add a tablespoon of water, but do not cut the 10 minutes simmering time short. Serve over steamed rice and garnish with sliced green onions and toasted sesame seeds.
