Season roast with salt and pepper. Brown all sides of roast in hot oil in a large skillet over high heat. Place in a 6-qt. slow cooker. Add banana pepper rings, beef broth, and garlic. Cover and cook on LOW 8 hours or until meat shreds easily. Transfer to a cutting board, reserving liquid in slow cooker. Shred roast; return to slow cooker. Keep warm on LOW. Preheat oven to 350°. Place tortilla chips on a baking sheet; top with shredded beef, black beans, tomatoes, onion, and cheese. Bake 10 minutes. Serve with cilantro, avocado, and sour cream.