Set a large frying pan over medium-high heat and immediately add the beef fry. Let cook 5 minutes per side, until fat is rendered and the beef fry gets crisp. Remove from pan, let cool and then finely chop. Reserve remaining fat.
Combine the chopped beef fry, ground beef, egg, bread crumbs, barbecue sauce, garlic powder, black pepper and salt together.
Slice pitas in half and gently stuff meat mixture inside, making sure not to rip the pita bread.
Brush reserved beef fry fat (or oil) over the pita and exposed beef and grill over medium heat for 5 minutes per side, until golden brown.