In a large skillet, heat over medium-high heat and add the lean ground beef and finely chopped medium onion. Sauté for 8-10 minutes, breaking the meat apart until browned.

Reduce heat to medium, add unsalted butter, garlic powder, ranch and au jus seasonings, sliced pepperoncini peppers, pepperoncini juice, and beef broth. Stir and cook for an additional 3-5 minutes until mixture thickens.

While beef mixture simmers, heat a separate skillet over medium heat. Add olive oil and toast prepped buns cut side down for 2-3 minutes until golden brown.

Once beef mixture is thick, spoon into toasted buns and top with coleslaw if desired. Serve hot and enjoy.