Add the frozen meatballs to a 6-quart slow cooker and sprinkle evenly with ranch seasoning and au jus mix (or brown gravy powder).
Pour in the beef broth, then top with the pepperoncini peppers and sliced butter.
Cover the slow cooker with a lid and cook on “LOW” for 5-6 hours, or on “HIGH” for 2.5-3 hours.
Serve hot with mashed potatoes, rice, egg noodles, or your favorite side dishes!
Notes
Storage: Transfer leftovers to an airtight container and store in the refrigerator for up to 3 days. Reheat portions as needed in the microwave until hot and steamy.Chicken meatballs: If you prefer, you can use frozen chicken or turkey meatballs in place of the beef meatballs used in this recipe.Using homemade meatballs: If you have a homemade meatball recipe that you love, feel free to use those instead of the frozen ones! Cook them all the way through before adding them to the slow cooker, and reduce the cooking time by 1 hour if using low, or 30 minutes if using the high setting.