Cut pork ribs into small pieces, brush with cooking oil.
Roast at 450°F/250°C for 20-30 minutes until golden. The purpose of roasting is to remove gamey taste and blood in pork ribs. (The pork ribs must be roasted until golden and fragrant in order to remove the gamey taste and blood in the meat.)
In a medium-size cooking pan over low heat, add oil, 1/4 cup rock sugar, and 2 tbsp water, constantly stir until the rock sugar is melted and caramelized. (During caramelizing the rock sugar, you should not be set the heat too high, otherwise, it will burn.)
Add 1 cup of boiling water, roasted ribs, Shaoxing cooking wine, garlic, light soy sauce, salt, 1 cup of rock sugar, 1/4 cup Zhengjiang sweet black rice vinegar, and 1 cup of water until the ribs are submerged in the sauce.
Turn up the heat and bring it to a boil. Cover the pan with a lid, turn the heat to low, simmer for 15 minutes; add 1/2 cup Zhengjiang sweet black rice vinegar, simmer for another 20-25 minute with the lid on, then add 1/2 cup Zhengjiang sweet black rice vinegar again, turn up the heat to high to thicken the sauce until all rib pieces are well glazed. (Add the Zhengjiang sweet black rice vinegar three times, especially the 3rd time is for enriching the flavor, therefore the dish is more flavourful.)
Plate and sprinkle white sesame seeds on top and serve!