You can very easily make a Christmas dinner for two for £60.
I'd spend a third to a half of it on good meat and the rest on vegetables and ingredients to make a desert.
Until Wednesday, Lidl are selling bags of sprouts, carrots and parsnips for 29p each. A large bag of floury King Edwards potatoes is less than £2. They also sell refrigerated jars of goose fat to roast them in.
By the time you throw in a few onions, eggs and milk (for Yorkshire puddings) and whatever else, it'll all probably cost under a Tenner. Then there's the meat. Lidl have a lot of special meats in for Christmas, including good sirloin beef joints, venison joints, lamb, duck and all the usual turkeys and chickens. You'll get a very nice bit of meat for around £20.
Aldi are currently selling legs of lamb for around £10-15, as well as the same sirloin beef joints, along with a huge range of turkeys and other meats for Christmas, including a £35 goose.
Then just buy some double cream, milk, custard powder, Swiss roll, jelly cubes, fruit and a bar of 85% cocoa chocolate to grate and you'll be able to make yourself lots of trifles for not much. Extra if you want to pour a bit of sherry or brandy over the Swiss roll. Or just buy a 750g sherry trifle from either Lidl or Aldi for £2.69. If you don't mind serving it from its plastic bowl, they both taste very nice, but are quite different recipes.
Christmas for £60 - Easy!
You should even have money left over for a few treats and nibbles. Also, if you want to take a gamble, you could go to the big supermarkets before they close on Christmas Eve and see if there are any fantastic bargains. I always leave the veg until last so it's fresh, and usually see many discounted food that has to be sold before closing because they're not open on Christmas Day and there won't be a big demand for many seasonal foods after that.
The various types of turkeys and posh meats tends to run out before Christmas Eve in Aldi and Lidl, so get them while they last.