In a small bowl, combine kosher salt, ground cumin, smoked paprika, garlic powder, onion powder, chili powder, dark brown sugar, ground red pepper and freshly ground black pepper. Mix well. Use in recipe below, and store unused rub in airtight container.
Prepare the Ribs
Place a piece of heavy-duty aluminum foil, shiny side down on a baking sheet. Place one slab of ribs on the foil and generously sprinkle each side with the prepared dry rub. Pat the dry rub into the meat to season it. Fold the foil over the slab of ribs to seal. Repeat this process with the second rib. Refrigerate for 3-5 hours.
When ready to bake, open foil and pour 1/2 cup of the beef stock in each packet. Reseal and bake for 4-5 hours in a 250 degree oven, until ribs are tender.
Transfer the ribs to a broiler pan and brush ribs with the baking liquid. Place under broiler for 3-5 minutes until glaze caramelizes. Slice each slab into 2 rib portions. Serves 6-8.