Pat mixture of first 4 ingredients into a 9" deep dish pie plate sprayed with nonstick cooking spray. Spread with ricotta cheese. Brown ground beef, garlic and onion in olive oil in skillet, stirring frequently. Add bell peppers and carrot. Cook for 2 minutes or until tender. Add tomatoes and tomato paste. Cook until bubbly, stirring often. Spoon over ricotta cheese. Sprinkle with mozzarella cheese. Bake at 350F for 20 minutes or until brown. Let stand for 5 minutes before serving.