Preheat oven to 400 degrees.
Brown ground beef and season with garlic powder (optional).
Warm up the container of frozen mashed cauliflower in the microwave according to package instructions.
Chop up the head of broccoli.
Mix browned beef, warmed mashed cauliflower and chopped broccoli together in a 9x13 baking dish.
Bake for 20 minutes.
Remove dish from the oven and sprinkle with shredded cheese.
Place dish back in oven until cheese has melted (3-5 minutes).
Remove from oven, let cool and enjoy!