Boxcar Barbecue
["1 (6 lb.) pork shoulder roast", "1 (28 oz.) can whole tomatoes, cut up", "1/2 c. vinegar", "1 (5 oz.) bottle soy sauce (2/3 c.)", "1 (5 oz.) bottle Worcestershire sauce", "1/2 c. packed brown sugar", "4 medium onions, chopped (2 c.)"]
["Place pork in shallow roasting pan.", "Combine undrained tomatoes with rest of ingredients.", "Pour over meat.", "Bake, covered, in a 350\u00b0 oven for 4 to 5 hours, until meat is tender. Uncover.", "Bake 1 hour more."]
["pork shoulder roast", "tomatoes", "vinegar", "soy sauce", "Worcestershire sauce", "brown sugar", "onions"]