Pop'S Barbecue Sauce
["2 medium cans tomato puree (8 oz. cans)", "1 1/2 to 2 c. vinegar", "1 stick margarine", "1 tsp. salt", "3 tsp. pepper", "6 tsp. mustard", "3 tsp. hot sauce", "1, 2 or 3 tsp. cayenne pepper", "1 (5 or 6 lb.) pork shoulder"]
["Cover pork roast with water and boil slowly until well done. Cool, then shred into small pieces.", "Mix sauce in pan and simmer for 30 minutes.", "Add meat and continue simmering, stirring occasionally, for about 1 hour.", "Serve on buns."]
["tomato puree", "vinegar", "margarine", "salt", "pepper", "mustard", "hot sauce", "cayenne pepper", "pork shoulder"]