I haven't even thought about that yet!
I know we'll probably be going to mass in the morning, so needing something relatively substantial. Especially as I have been muttering about a Christmas Day swim later (tides are not great - but it looks like it should be decent from about 12.30 onwards to get in). Although mass will have options of 10.30 am, noon, or 9pm ("midnight mass"!) on Christmas Eve. Hmm, I think I need to do some thinking around timings.
Anyway, we often have bacon butties, or make up jus-rol croissants in the oven. Although we've found M&S frozen raisin Danish to oven bake which work great too.
There will definitely be freshly squeezed juice - I love grapefruit but DH and DD go for orange.
And lots of hot coffee for DH and I.
DD will have sweets and fruit in her stocking that will help fill her up too.
I would love to plan some of the sumptuous breakfasts you see here and in food magazines and cookery programmes - but they never work out.