Oxford Bishop, Oxfordshire
Curse central heating! We used to keep warm by consuming far more calories, and even more pleasantly by drinking mulled wines and ales, and other delights such as Oxford Bishop.
Bishop is also known as Steaming Bishop (it may ring a tiny bell in your head chiming Christmas Carol - Scrooge promises some to Bob Cratchit when he turns over a new leaf on Christmas Day). The name almost certainly refers to the purple colour of the drink, like a bishop's robes, as the basis is port.
Oxford Bishop is the most refined version of the drink, as befits such a place of learning and culture in spite of the undergraduates, said to have been drunk in the common rooms there on cold winter's nights. Simple Bishop or Steaming Bishop is made with a roasted orange rather than a lemon as used in the Oxford variant.
This is no instant mix: a lemon stuck with cloves is roasted for 20 minutes or so to remove its sourness and bitter tang, while a half pint of water is heated with a good dollop of spice: anise, cinnamon bark, nutmeg in pieces, allspice berries, and a couple more cloves, though they were perhaps more to 18th and 19th century tastes than ours. Whole spice must be used, to avoid clouding the final brew.
When the water has reduced by around half, add the roasted lemon and three quarters of a bottle of cheap port - ruby is fine, vintage is criminal - and heat it through without allowing it to boil. Sweeten with a couple of ounces of sugar and taste for the results, along with the juice and grated zest of a fresh lemon, and the remainder of the bottle of port to cool the liquid a smidgen. Strain the liquor into a serving jug or carefully warmed punch bowl and enjoy. If using the bowl, transfer the clove-studded lemon to it for decoration.
Dickens was evidently fond of Bishop, mentioning it in The Pickwick Papers and Nicholas Nickleby as well as A Christmas Carol. It is definitely to be drunk with caution as port has quite a kick, though it is a more satisfying drink than mulled wine, and more impressive. But remember what Dickens said of Scrooge at the end of the tale: "It was always said of him, that he knew how to keep Christmas well."