Shivvy, that same Christmas I bought veggie bacon and sausages, and a ready made veggie roast thing from the supermarket. The bacon was difficult to wrap round the sausages as it wasn't very flexible, and cracked a bit, but they went down well with our two veggie relatives.
The roast thing was really tasty, there are lots of special ones to choose from around Christmas if you don't want to make one yourself.
The rest of the meal was the same as everyone else, really easy and no faff at all.