Breakfast… either way you do it
Get an early ADR for breakfast so you can enter MK before it opens. It’s a unique opportunity to take pictures of your family in front of the castle with no one else in the background!
Or, like Soundgod suggested, do a late breakfast ADR and wait for them to turn it into the lunch buffet.
With buffets, breakfast is just the “safest” food. It’s standard… you can’t really mess it up.
Now, I’ve eaten at CP for dinner and lunch before, and I’ve liked both of those meals, too. But breakfast is the least expensive and imo, it offers the most bang for your buck.