Season the short ribs with salt and pepper, to taste. Warm the oil in a large skillet over high heat. Add the ribs and brown until golden, turning them once, about 8 minutes. Transfer the ribs to a paper towel-lined plate. Pour the wine and coffee into the skillet. Cook over high heat, scraping up the brown bits on the bottom, until the sauce is reduced by one forth, about 2 to 3 minutes.
Put the ribs, onion, garlic, 2 teaspoons salt, the chili powder and oregano in a slow cooker. Pour in the wine sauce and cook, covered, on high for 3 1/2 hours. Uncover and cook until the ribs are falling apart, about 45 minutes more. Transfer the ribs and sauce to a serving dish and serve.