1. Heat oil in stockpot over medium heat until hot. Place beef roast in stockpot; brown evenly. Pour off drippings; season with salt and pepper, as desired.
2. Add beer, peppers and 2 tablespoons adobo sauce to stockpot; bring to a boil. Reduce heat; cover tightly and simmer 2-1/4 to 2-1/2 hours or until pot roast is fork-tender.
3. Meanwhile, combine coleslaw and remaining 1 teaspoon adobo sauce. Refrigerate until ready to use.
4. Remove roast; cool slightly. Skim fat from cooking liquid; bring to boil. Reduce to medium and cook 10 to 12 minutes or until reduced to 1-1/2 cups. Meanwhile, trim and discard excess fat from cooked roast. Shred roast with 2 forks. Return beef to reserved liquid; cook over medium heat until heated through.
5. Serve beef in tortillas; top with coleslaw mixture and toppings, as desired.