Let me suggest you focus on the"gathering of peoples in God's Kingdom" which Jesus' refers to as the Feast of Abraham. That's the bigger miracle here than simply the Centurion's servant healing. Like MOST miracles, Jesus uses them to illustrate a broader point. (Reminds a lot of Elijah saving the Widow's son, doesn't it. Zarephath was outside of Israel and she was not a Jew.)
Apparently this Feast Day was celebrated in the time of Jesus since he references it. Medieval Jews and Muslims seem to have celebrated it.
One source I came across celebrated it with honey cakes ---aka "journey cakes", or "Johnny Cakes" as they say in the islands.
The theme of Abraham the traveler, and the centurion who was a foreigner in Jesus' land and culture fits with Jesus words: "People will travel from east and west" as Jesus said. Which is to say "outsiders like the centurion" will travel to meet Jesus, ---to join at God's table. (We use this line in communion liturgy too).
What is our food for the journey? (here is where the cooking lesson could expand beyond just making "Johnny" cakes. Dough can be made into maps, journey scenes, "things you need for the journey". And the gift of a journey cake is something you can share.
What is the journey like?
How did the centurion hear about Jesus? Who told him? Who do we tell?
Hazards? Helps? ...For the centurion? for us?
Read this enlightening article about an interfaith feast day that was created based on the centurion story and Abrahamic Feast concept:
If the link breaks, it's the Feb 26, 2011 Sarasota Herald Trib article.
In short, it's a kosher meal for the descendants of Abraham hosted by a priest, a rabbi and a Muslim prayer leader that's grown to over 200 attendees.