Breakfast booking manager for hotel

Hotel manager want his guest can book breakfast in advance, so he can avoid "mass people" in the bar area at the morning.

He want a calendar where guests choose time for his breakfast;
I don't know long how this "time-frame" should be (I mean, 5 minutes long, 10 minutes long, 15 minutes long, or more..) and how many booking he can accept for each time-frame.
I suppose only 1 booking for time frame, so if I book (example) my breakfast for time 07:30 AM - 07:40 AM, then this slot should be UNavaible to other guests.
Point is: guest book breakfast, then he can pick up your breakfast in the morning and find it ready.

Sayd that, he want to permit to guest to choose which plates they want for their breakfast, so hotel manager should have an admin area where he can insert plates (and other stuff, like coffee, cappuccino, water, and all hotel manager want to add in the breakfast..) with an image too (better to have image, so guests can "see" the plates).
Once he add plates to the menu database, he can choose which plates is available for breakfast on tomorrow, or next days.. This up to you how you want to solve that. Point is: once foods are on dabatase (each one whith his own photo), he can choose which is available day-by-day (maybe selecting day on calendar?!)

Guest don't need any registration to book breakfast (appplciations will be installed on a subdomain, so only his guests can know the URL);
OR... you can think a system with of a master password that hotel manager can change each day, so each day he have to comunicate the new breakfast password to his guests.
Good idea!

In booking form, guests only have to choose which foods they want, how many for each plates, and number of room they have at the hotel, with a field too to write down his name (so hotel managers can check his guest don't make any mistake in room number, writing down a wrong number, as example..)