Lenten "Seder"
Hosting an adapted "Seder Meal" is something many churches have done during Lent. The Seder is the ritual re-enactment of the Passover story which many Christian churches have adapted to include elements of the Last Supper story and Communion. Check out Rotation.org's Passover - Seder Forum for several ideas.
Also take note that our Writing Team has written a Sunday School Last Supper "Seder" lesson (with script) for children for its Last Supper lesson set, and a "Seder-like" meal lesson for its "Story of the Cross" Cooking workshop lesson (both open to supporting members)
Lenten "Purim" festival - "the Jewish Mardi Gras"
Purim celebrates the biblical story of Esther and the Jews victory over Haman and his forces of evil. Purim's "carnival-like" celebration, complete with costumes and humor, has been called "The Jewish Mardi Gras" ...laughing in the face of evil, knowing that salvation is the Lord's. Both Purim and Passover celebrate FREEDOM and the overthrow of a tyrant.
The Purim and Passover are like bookends, one ecstatic and humorous, the other worshipful and serious. In that way, they are much like "Shrove Tuesday" (or Mardi Gras, literally: "Fat Tuesday") and Lent itself.
Go to Rotation.org's Esther ~ Purim forum for lesson and celebration ideas.