Lightly grease the inside of the slow cooker/crock pot with cooking spray; set aside.

In a large mixing bowl combine eggs, milk, salt, pepper, garlic powder and chili powder. Using egg beaters or a whisk, beat the mixture until mixed and well combined. Add broccoli florets, sliced peppers, onions and garlic to the slow cooker; stir in the egg-mixture.

Cover and cook on HIGH for 2 hours. Start checking it at 1 hour 30 minutes; casserole is done when eggs are set. Sprinkle with cheese and tomatoes and cover; let stand 2 to 3 minutes or until cheese is melted. Turn off slow cooker and enjoy!