1 (2 1/2 - 3 pound) boneless pork sirloin roast
1/2 tsp salt
1/2 tsp pepper
1 tbsp oil
2 medium onions, cut into thin wedges
1 cup Root Beer
3 cups Root Beer
1 cup bottled chili sauce
1/4 tsp Root Beer concentrate, optional (found in the baking aisle with the other extracts)
several dashes hot pepper sauce, optional
toasted hamburger buns
Trim the fat from the pork roast. If necessary, cut roast to fit the crock pot. Sprinkle pork with salt and pepper. In a large skillet, brown roast on all sides in hot oil. Drain off fat. Transfer the roast to a 3 1/2 - 5 quart crock pot. Add the onion wedges and 1 cup Root Beer. Cook, covered, on LOW for 8-10 hours, or HIGH for 4-5 hours.
Meanwhile, for the sauce, combine the 3 cups Root Beer and chili sauce. Bring to a boil; reduce heat. Boil gently, uncovered and stirring occasionally, about 30 minutes, or until mixture is reduced to 2 cups. If desired, add the Root Beer concentrate and hot pepper sauce.
Transfer the roast to a serving platter. With a slotted spoon, remove the onion from the juices and set aside. Discard the juices. Using two forks, pull the pork into shreds. To serve, add the pork and onions to the buns, and spoon on the sauce.