Put all the ingredients in a large mixing bowl and stir. Add some beer if it seems too stiff and get every member of the family to give it a stir and make a wish before you put it into a 1-litre pudding basin. Cover the top with a double layer of greaseproof paper and tie round the edge with string. Put on a trivet in a pan with water in the bottom, cover and steam for 1 hour 30 mins to 2 hours (insert a knife; it should come out not too sticky). Cool and store in a cold, dark place until christmas.