DS is in reception and takes packed lunch as he's a bit too much of a fusspot for school dinners. On the day of school Christmas dinner I've told him that I'll make him a Christmassy packed lunch so he wouldn't feel that he was missing out.
I'll make his sandwiches with Christmas cookie cutters and try to get a little christmassy cake or biscuit, but what else can I include?
I'd check how many children take packed lunches on the day of the Christmas Dinner. Where I work 99% of children have the Christmas Dinner when normally it's half dinners, half lunchboxes. Even if they don't eat much they feel part of the fun! EVERY child gets a cracker, music plays and the teaching staff wear silly hats and clear up but for some reason those with a Christmas Dinner seem to have more fun!