These succulent ribs, a version of those served at Korean restaurant Do Hwa, are adapted from the cookbook Dok Suni: Recipes from My Mother's Korean Kitchen by Jenny Kwak, whose mother owns Do Hwa.
In a large roasting pan set over 2 burners, cover the ribs with cold water and bring to a boil over moderately high heat. Boil for 5 minutes. Transfer the ribs to a large plate; discard the water.
Return the pan to the 2 burners and add the water. Add the ribs and ginger; bring to a boil. Add the sugar, garlic, soy sauce, sesame oil and chile flakes. Cover with foil and boil over moderately high heat for 7 minutes. Simmer over moderately low heat, turning the ribs a few times, until tender, about 20 minutes.
Preheat the broiler. Transfer the ribs to a large rimmed baking sheet, meaty side down. Boil the braising liquid until thickened and intensely flavored, about 10 minutes. Strain the liquid; you should have about 2 cups.
Generously brush the ribs with the braising liquid and broil 4 inches from the heat, rotating the pan, until glazed and lightly charred, about 3 minutes. Turn the ribs meaty side up and brush again with the braising liquid. Broil, brushing occasionally and rotating the pan, until the ribs are glazed, about 4 minutes. Let rest for 5 minutes, then cut between the ribs, mound on a platter and serve.