Sear the Pork Belly: Heat the vegetable oil in a large skillet or wok over medium-high heat. Add the pork belly cubes and sear until golden brown on all sides, about 5-7 minutes. Drain any excess fat.

Prepare the Sauce: In a bowl, whisk together the soy sauce, brown sugar, rice wine, hoisin sauce, honey, garlic, ginger, and Chinese five-spice powder.

Simmer the Pork: Add the sauce mixture to the skillet with the pork belly. Pour in the water and stir to coat the pork. Bring the mixture to a simmer.

Cook Low and Slow: Reduce the heat to low, cover, and let the pork belly cook for about 1 hour, stirring occasionally, until the pork is tender and the sauce has thickened. If the sauce reduces too much, add a little more water.

Caramelize: Remove the lid and increase the heat to medium. Let the sauce cook down for 5-10 minutes, stirring occasionally, until it becomes sticky and coats the pork belly pieces.

Serve: Transfer the sticky pork belly to a serving plate and garnish with sliced green onions and sesame seeds if desired.