Heat oven or outside covered grill to 450°F. Spray pita bread with cooking spray (both sides). Spread 1 tablespoon pesto sauce on each pita. Sprinkle ¼ cup of mozzarella cheese on each pizza. Place quartered artichokes (four pieces) on each pizza. Sprinkle pizza with chili flakes & 1 tablespoon of grated Parmesan cheese.
Place pizzas directly on oven rack or outside grill rack. Bake for 3-5 minutes until cheese melts and pitas are crispy. Cut each pita pizza into four wedges and serve.