We've got a similar thing in a couple of weeks so I've been having just the same thoughts as you. At this time of year, life can be so busy and hectic that I wouldn't feel too guilty about taking something shop-bought. A couple of other really simple ideas
that I've had are here though:
160g plain flour
70g unsalted butter
1. Preheat the oven to 180 degrees C (160 degrees fan or gas mark 4)
2. Rub the butter and flour together in a mixing bowl until the mixture resembles breadcrumbs.
3. Add the cheese and beaten egg and mix together until combined.
4. Sprinkle out a little flour and roll out the dough. Cut shapes from the dough using a cutter (perhaps star shaped or something else suitably Christmassy if you have the cutters).
5. Put the shapes on baking parchment in a baking tray. Bake for 10-12 mins until just golden.
Running out of characters so will do a new answer with the other recipe...