Add the cauliflower rice and broccoli florets to the skillet. Cook, stirring occasionally, until the cauliflower rice has softened slightly, about 5 to 7 minutes. If using frozen rice, cook until most of the moisture has evaporated.
In a separate bowl, whisk together the softened cream cheese, chicken broth, heavy cream, salt, pepper, and garlic powder until smooth.
Add the shredded chicken and half (1/2 cup) of the cheddar cheese to the skillet mixture. Stir well to combine.
Pour the chicken and cauliflower mixture into the prepared baking dish. Spread it evenly.
Top the casserole evenly with the remaining 1/2 cup of cheddar cheese.
Bake for 20 to 25 minutes, or until the casserole is bubbly and the cheese on top is melted and lightly golden brown.
Let the casserole rest for 5 minutes before serving.
Notes
For a lighter version, substitute the cream cheese with plain Greek yogurt, though the texture will be less rich.
You can use rotisserie chicken for faster preparation on a busy weeknight.
This recipe is naturally gluten-free and keto-friendly.