Hong shao rou is the dish Chairman Mao is said to have eaten weekly and it remains the benchmark for home-style red braising. Pork belly is caramelised in melted sugar, then simmered in soy, Shaoxing and spices until the fat turns to jelly and the sauce reduces to a dark lacquer.
Two things make or break it. Blanch the pork first so the braise stays clean, and take the caramel to a proper amber before the meat goes in. Everything after that is just time on a low heat.