Preheat oven to 350 F.
Season the outside of the ribs with coarse salt. Place ribs in a roasting pan on a rack. Pour water into the bottom of the roasting pan just enough to cover base of pan (about ½ – 1 inch up sides). Do not allow water to touch the meat. Top ribs with slices of onion, lemon and garlic. Cover roasting pan with foil and place in the preheated oven for about 2 ½ hours. Allow to cool. Refrigerate until ready to use.
Preheat grill. Place ribs on grill but not directly over the flames or coals. Brush ribs with a generous amount of barbeque sauce and grill for 15 minutes, turn over and reapply sauce. Cook for a further 15 minutes or until nicely glazed.