Preheat oven to 375°F.
Cook onion in olive oil in until softened, about 5 minutes.
Add chicken broth and bring to a boil. Stir in rice, cover and turn off heat. Let sit covered 5 minutes.
Steam broccoli until tender crisp.
In a large bowl combine cooked rice, cream of mushroom soup, cream of chicken soup, sour cream, milk, seasonings, turkey, broccoli and 1 ½ cups cheddar cheese.
Spread into a greased 9×13 pan.
Combine topping ingredients in a small bowl. Sprinkle over casserole and bake 35 minutes or until hot & bubbly and lightly browned. Serve warm.
