In a large pot, combine the rinsed quinoa and chicken broth. Bring it to a boil, then reduce the heat, cover, and let it simmer for about 15 minutes or until the liquid is absorbed. Fluff with a fork once done.
While the quinoa is cooking, heat the olive oil in a skillet over medium heat. Add the diced onion and minced garlic, sautéing until fragrant and the onions are translucent, about 3-4 minutes.
In a mixing bowl, combine the cooked quinoa, shredded chicken, sautéed onions and garlic, broccoli florets, half of the cheddar cheese, milk, Greek yogurt, salt, pepper, garlic powder, and onion powder. Stir until everything is well mixed.
Preheat your oven to 350°F (175°C). Transfer the mixture into a baking dish and spread it evenly. Sprinkle the remaining cheddar cheese on top.
Bake the casserole for about 25-30 minutes, or until it’s bubbly and the cheese is melted and slightly golden on top.
Once out of the oven, let it cool for a few minutes before serving. Enjoy this comforting dish with your family and friends!