For the barbecue sauce: In the bowl of a blender, combine the ketchup, apple cider vinegar, molasses, mustard, garlic, chipotles and sauce and onion. Season generously with salt and pepper. Blend until smooth.
For the ribs: In a small bowl, combine the garlic powder, paprika, brown sugar, cayenne, chili powder, 2 tablespoons salt and 2 teaspoons black pepper. Sprinkle the ribs with the rub on all sides.
In a skillet, warm the olive oil over medium-high heat. When shimmering, add the ribs and brown on all sides, working in batches if necessary. Transfer to a slow cooker.
Add the barbecue sauce, Mexican oregano and enough chicken stock to come halfway up the ribs. Set the slow cooker to high and cook, 8 to 10 hours. Remove the ribs and shred the meat into bite-sized pieces. (Discard the fat.) Taste the sauce and adjust the seasoning if necessary. Whisk to combine (the sauce may separate during cooking) and transfer to a serving bowl.
Construct tacos by spreading the tortillas with sauce and topping with pork, cucumbers, avocado wedges, cabbage, Cotija, radishes, pico de gallo and cilantro. Serve immediately with lime wedges.
Recipe courtesy of Eddie Jackson