I’m pretty sure the following summarizes an appropriate and restrained response to the prospect of Christmas and/or boxing day lunch:
Merry belated Christmas.
PS. Ham causes the apocalypse is perhaps the most accurate and certainly the funniest summation of the plot of ponyo I can think of.
Hamageddon. Pork of Eli. My Ham Legend. The Salted Dead. 2012, but also there’s ham.