The pool deck buffet. Service ends PROMPTLY at 8:30. You can sit up there and eat after that time, but there will be no more food served--fill your plate before 8:30.
Room service is available to concierge cabins only.
Of course, if you want only cereal, milk, and juice you can order from room service the evening before and store it in your refrigerator/cooling box. A glass of ice in the cooling box keeps everything really cold.