Preheat your oven to 350°F (175°C) to prepare for baking the casserole.

In a large bowl, mix the shredded chicken, broccoli florets, cooked rice, Greek yogurt, chicken broth, Dijon mustard, garlic powder, onion powder, salt, and pepper until well combined.

Pour the mixture into a greased 9x13 inch baking dish and spread it evenly.

If desired, sprinkle shredded cheese on top of the casserole.

Bake in the preheated oven for 25-30 minutes, until heated through and bubbly.

Let it cool for a few minutes before serving to enjoy the delicious flavors!