Preheat oven to 375°F (190°C). Lightly grease a 9x13-inch casserole dish.

In a medium saucepan, bring quinoa and water or broth to a boil. Reduce heat, cover, and simmer for 15 minutes, or until liquid is absorbed. Fluff with a fork.

In a large skillet, sauté the broccoli for 3-4 minutes (if using fresh). If using frozen, thaw and drain before adding to the pan.

In a large mixing bowl, combine cooked quinoa, shredded chicken, steamed broccoli, cheddar cheese, Parmesan cheese, Greek yogurt, milk, garlic powder, onion powder, salt, and black pepper. Stir until well mixed.

Transfer the mixture to the prepared casserole dish and spread evenly.

For a crunchy topping, mix breadcrumbs with olive oil or melted butter and sprinkle on top of the casserole.

Bake uncovered for 25-30 minutes, until the casserole is bubbly and the top is golden brown.

Let rest for 5 minutes before serving.