Try to check in right at 14:15 - you will physically there, after all. Unless you get a by-the-book agent who for some reason forces you to wait until exactly 15:30, I suspect they will be willing to get you out on your way at opening time. It makes their workday easier, after all.

Either way, you are correct that pre-security food is practically non-existent. The trick will be to either eat breakfast before leaving for the airport, or bring a snack (breakfast burrito, maybe) to tide you over before you can access the good food post-security.