1. Preheat oven to 300 F.
2. Coat ribs generously with salt and pepper on both sides. Heat oil in Dutch oven over medium high heat. Add ribs, and brown all sides of the ribs. Remove ribs from heat once browned and set aside.
3. Lower temperature of Dutch oven, and add in onions and garlic. Stir-fry for 3-4 minutes until ingredients become tender. Add in cumin seeds, cinnamon stick, allspice, oregano, and bay leaves. Stir for 1-2 minutes. Add in chilies, beer, broth, brown sugar, and stir ingredients again. Place ribs inside liquid.
4. Raise temperature to high and bring to a boil. Cover with a lid or 3 layers of aluminum foil. Place in the middle of the oven and let bake for 3 hours without uncovering.
5. Slice the onions into thick rings and stir-fry until onions are caramelized, for 10 minutes.
6. Remove meat from oven after 3 hours. Using a fork separate meat from bone and fatty parts and set meat aside. Toss meat with a few tablespoons of juices from pot to avoid meat from drying out quickly.
7. Place cheese on tortillas, then place directly on the racks inside a 350 F oven, until melted. Remove tortillas from oven and add meat, caramelized onion, cilantro and salsa. Serve warm.