Pat the pork spare ribs dry with paper towels. Use a sharp knife to lift and remove the membrane attached to the bone in one piece. Trim off any excess fat.

Season the ribs with sea salt, cut them into individual portions, and let them rest for 20 minutes.

Heat oil in a frying pan and fry the ribs until golden brown. Transfer the ribs to a platter and set aside.

For the sauce: Heat a stainless steel frying pan with a little oil. Melt the sugar to make a caramel, cooking until it turns golden brown. Be careful not to burn the sugar—if small bubbles appear on top, the caramel is burned and should be discarded to avoid a bitter taste.

Carefully add the boiling water to dissolve the caramel, keeping your distance as the water may splatter. Add the Shaoxing rice wine, dark soy sauce, black rice vinegar, scallions, and ginger.

Place the ribs in the sauce, bring to a boil, then reduce the heat. Cover and simmer for 50 minutes.

Remove the cover and let some of the liquid evaporate to thicken the sauce. Return the ribs to the pan and coat them with the sauce. Cook for another 10 minutes.

Transfer the ribs to a serving platter. Strain the sauce and pour it over the ribs. Sprinkle with toasted sesame seeds before serving.