1. In a small jar with tight-fitting lid, shake together all dry ingredients until well-blended. Rub dry mixture onto all surfaces of ribs.
2. Make a container for ribs by taking double layer of heavy-duty foil just large enough to hold ribs; crimp edges to make 1" sides.
3. Preheat gas grill to medium-low heat. Add ribs in foil container and grill in covered grill, turning occasionally, until ribs are very tender and juicy, about 1 1/2 hours (OR roast ribs on rack in shallow pan in 350degF oven for 1 1/4 to 1 1/2 hours). Cut into 1-or 2-rib portions to serve.