Label a two-gallon freezer bag with the name, date, cook time and instruction to thaw. Add beef, peppers, onion, pepperoncini, brine, broth, oregano, basil, garlic powder, salt and pepper.
Press out excess air, seal, support on a tray and freeze flat for up to 3 months.
Thaw completely in the refrigerator for 36 to 48 hours and empty into a 6-quart slow cooker.
Cover and cook on low for 8 to 8 1/2 hours, until the beef pulls apart easily.
At dinner, shred the beef into the juices and fill the rolls with drained beef and peppers.