In a large mixing bowl, combine the cooked rice, shredded chicken, broccoli florets, half of the cheddar cheese, cream of mushroom soup, milk, garlic powder, onion powder, and dried thyme. Mix well until everything is evenly coated. Season with salt and pepper to taste.
Transfer the mixture into a greased 9x13 inch casserole dish, spreading it out evenly.
In a small bowl, combine the breadcrumbs with olive oil and a pinch of salt. Mix until the breadcrumbs are evenly coated with the oil.
Sprinkle the breadcrumb mixture over the top of the casserole, then add the remaining cheddar cheese on top.
Bake in the preheated oven for 25-30 minutes or until the cheese is bubbly and the breadcrumbs are golden brown.
Once done, remove from the oven and allow to cool for 5-10 minutes before serving.
Notes
Serve hot, garnished with fresh parsley or chives.