If you are
Add Dishes as Attendee Types
Create attendee types to use as the dishes people can sign up to bring.
Make sure you enter the maximum number of dishes by clicking Edit Capacities.
Get Any Extra Information
Add any questions you need answered in order to make sure the food gets where it belongs.
Invite People to Sign Up
Once the event is created, send the link to those who will want to sign up for a dish. When they go to the link, they can click Register to choose what type of dish they want to bring.
The person will choose what type of dish they'll be bringing as their attendee type, answer any questions you've added, and receive a confirmation email once they've finished registering.