| 4 pounds pork back ribs, cut into serving-size pieces |
| 2 teaspoons each salt, pepper, chili powder and ground cumin |
| 1 small onion, finely chopped |
| 2 tablespoons butter or margarine |
| 1/4 cup packed brown sugar |
| 3 tablespoons lemon juice |
| 3 tablespoons worcestershire sauce |
| 1 1/2 teaspoons ground mustard |
| 1/8 teaspoon cayenne pepper |