- FOR THE POT ROAST:Position rack in center of oven and preheat to 350 degrees F. Combine salt, pepper, basil, and oregano in small bowl. Rub spice mixture generously over entire brisket.
- Heat oil in heavy large Dutch oven over medium-high heat. Add meat and cook until brown, about 4 minutes per side. Transfer meat to platter. Set aside.
- Add broth and beer to Dutch oven. Using spatula or spoon, scrape up any browned bits from bottom of pot. Bring to boil. Return brisket to pot fat side up. Sprinkle onions and garlic over brisket.
- Cover pot and bake 1 hour. Arrange onions under brisket. Bake uncovered 1 hour, adding more liquid, if necessary, and stirring onions halfway through baking time. Turn brisket over. Cover and continue cooking until fork can easily be inserted into meat, about 1 1/2 hours longer. Cool meat in sauce.
- DO-AHEAD TIP:Pot roast can be made 1 day ahead. Transfer meat to resealable plastic bag and refrigerate. Pour sauce and onions into storage container and refrigerate.
- Preheat oven to 400 degrees F. Slice meat across grain into 1/2-inch-thick slices. Arrange slices in large baking dish.
- Strain sauce into 4-cup glass measuring cup. Transfer onions to medium saucepan. Spoon fat from atop sauce. Pour sauce over meat. Cover baking dish and bake in oven until heated through, about 25 minutes. Rewarm onions over medium heat, about 8 minutes.
- FOR THE SANDWICHES:Spoon warm onions into serving bowl.
- Place rolls in serving basket. Place roasted red bell peppers, cherry peppers and pepperonicini in separate serving bowls. Allow guests to assemble sandwiches by dipping rolls into sauce; filling rolls with meat, topping with onions and any or all of various peppers and hot pepper sauce.