My culinary school is hosting a food drive and has asked me to make food for an event

I go to a culinary school and they're asking everyone to bring in their favorite recipe to make and give to an event my school is hosting. They are collecting food donations for a local food bank and will have a banquet (for donors) with the food we make. We all get a few hours to make the dish in our kitchens and have a budget of $20. What should I make for the event? And should I partner with someone on this or should I go solo?