In a small bowl, combine the 1 tbsp of browning with ½ tsp of liquid smoke. Pour mixture over the oxtails and mix until each oxtail is well coated.

Sprinkle over the oxtails 1 tsp garlic powder, 1 tsp onion powder, 1 tsp paprika, 1 tsp black pepper, 1 tsp salt and ½ cup brown sugar and 1 tbsp of cornstarch. Toss everything together until the oxtails are thoroughly coated with the seasonings.

In a separate bowl, combine 3 cups of barbecue sauce with 2 cups of water. Stir in 1 cup of beef broth and ¼ cup bourbon until well mixed.

Preheat your oven to the required temperature for slow braising to 350°F. Arrange the seasoned oxtails in a cast iron skillet or a similar oven-safe dish. Pour the prepared barbecue sauce mixture evenly over the oxtails.

Cover the dutch oven tightly with a lid or aluminum foil. Place the covered dutch oven in the preheated oven. Cook for about 5 hours, or until the oxtails are tender and reach your desired level of doneness.Remove the Dutch oven from the oven, uncover, and let the oxtails rest for a few minutes before serving. Optionally, you can skim off any excess fat from the top of the sauce. Serve