Preheat oven to 400°.
Cook onion, garlic, and beef in a large nonstick skillet over medium-high heat until beef is browned, stirring to crumble. Add tomato paste, 1/4 teaspoon salt, pepper, and tomatoes; bring to a boil. Reduce heat, and simmer 5 minutes.
Steam broccoli, covered, 4 minutes or until tender. Drain. Place broccoli, 1/4 teaspoon salt, ricotta, basil, Parmesan, and juice in a blender or food processor; process until broccoli is finely chopped. Spread about 1/3 cup broccoli mixture over each pizza crust, leaving a 1/2-inch border; top with 1/3 cup beef mixture.
Place pizzas on a baking sheet. Bake at 400° for 18 minutes or until heated.