1. Toss the ribs in salt and pepper. Heat the oil in a large roasting pan and fry the short ribs until each side is very dark and well-caramelized. Don’t skimp and it may take up to an hour to get them all done. If your pan isn’t big enough, you can brown them in batches, or do some in a separate pan.
2. Remove the ribs from the pan, then turn off the heat and deglaze the pan with the beer. Scrape up the browned bits stuck to the pan with a firm spatula, then add the garlic and ginger, stirring to cook them in a residual heat of the pan.
3. Preheat the oven to 325F. (160C)
4. Add the ribs back to the pan and mix in the vinegar, chocolate, and chili powder.
5. Cover and let simmer for 3 hours, turning the short ribs a few times while they’re cooking. The ribs are done when they’re fork-tender and falling off the bone. (During cooking, you may need to add a bit of water to the pan if the liquid evaporates too much.)
6. Remove the cover, stir in the hoisin sauce, reduce the heat to 300C (150C) and cook for another 30 minutes.