Ingredients : 4 lbs pork (shoulder roast) ½ cup ketchup ½ cup chicken broth ½ cup water ¼ cup cider vinegar ¼ cup brown sugar   2 tbsp oil 1 onion chopped 3 cloves garlic chopped Salt and pepper to taste   1 tsp dried tarragon herb 1 tbsp chili powder 1 tsp Black Kettle Spice …