Preheat the oven to 400°F. In a medium skillet, cook beef, onion, and garlic until beef is browned. Slowly stir in Neapolitan sauce and rosemary, bring to a boil, then reduce heat and simmer for 2 minutes.
Split pita rounds in half horizontally using a sharp knife. (You are turning 2 pita breads into 4.) Place each pita round, rough side up, on a baking sheet and bake for 3 minutes.
Top toasted pita rounds with meat mixture, sprinkle with mozzarella cheese, and bake for 2-3 minutes or until cheese is melted. Remove from the oven and top with spinach, tomato, feta cheese, and olives. Serve warm.
Notes
I always use 93% (or better) lean ground beef in order to limit calories and fat as much as possible.