In a large saute pan, melt butter over medium heat. Add diced onion and stir regularly until soft and translucent, about 5 minutes.
Add ground chicken and break apart while cooking till no longer pink, about 5 minutes. Add salt and pepper to taste (start with about 1/2 tsp salt and 1/4 tsp pepper - you could add 1 tsp chicken bouillon instead for a flavor boost)
Add minced FRESH garlic and stir for 1 min. Do not burn!
Pour frozen riced cauliflower into the pan and stir with chicken/onion/garlic mixture for about 4 minutes (add a small splash of water or chicken broth if the mixture gets dry).
Add frozen broccoli florets and continue to stir occasionally until broccoli is to your desired tenderness. Add a lid to speed up the cook time for this step.
Sprinkle shredded cheddar over the whole pan and stir gently to combine/melt the cheese. Serve right away and enjoy!