1Heat oven 400°. Spray cookie sheet with cooking spray. Roll or pat pizza dough into 13x9-inch rectangle on cookie sheet. Sprinkle with garlic and rosemary. Arrange onion rings evenly over dough. Sprinkle with cheese.
2Bake about 12 minutes or until cheese just begins to brown. Lightly spray focaccia with cooking spray; sprinkle with salt. Cut into 6 wedges. Serve immediately.