Firstly clean the ribs and then soak in clean water for 15 minutes.
Add ribs in water with green onion and slices of ginger. Bring the pot of water to a boiling and then continue cooking 1 to 2 minutes to remove the impurities and odd taste. Pick ribs up and then drain because we are going to sauté them later.
Add around 1 tablespoon of oil in wok or pan and fry the ribs with middle fire until the surface becomes slightly browned. This step can improve the aroma. Then add ketchup, salt, light soy sauce, vinegar, sugar and enough water to cover the ribs. The simmer for 25 minutes over slow fire. Stay covered.
During the process, mix cornstarch with water. Add starch water to help thickening the sauce. Sprinkle some toasted white sesame seeds before serving.