1. Preheat oven to 250 degrees Fahrenheit.
2. Heat oil in a Dutch oven over medium-high heat. Season ribs with salt and pepper, then sear on all sides. Remove from pan.
3. Add sugar, soy sauce, ginger, garlic, sesame oil, red pepper and beef stock. Bring to a boil. Return ribs to pan (you want the ribs to be covered with liquid, so if they’re not, add a little more beef stock), cover, and transfer to the oven.
4. Bake for three hours.
5. Remove from oven. Remove ribs from pan and set aside. Transfer the pan to the stove and cook over medium-high heat, until sauce is reduced and thickened. Return ribs to pan and toss to coat. You can either set aside to rewarm later, or top with sesame seeds and scallions and serve.