Hey,
First of all again its really great what you have done. I do not want to demand anything, here are just some ideas I have:
1)
It would be great to have an option that everytime a new order comes in an email to the restaurant is sent out.
2)
If a staff´s only permission is to see orders, it would be nice if the interface is showing nothing else but the orders.
3)
An option to print an order summary/invoice