To drink, Lucozade isotonic sport (non-fizzy, orange flavour). Rehydrates brilliantly. If you haven't got any, a little orange juice mixed with tonic water.
To eat, Something very carb heavy, such as pasta, but with a non-acidic sauce, so not too heavy on tomato. Or, if you can't stomach that, a fried egg sandwich.
The best thing is a Bloody Mary, of course - with lots of tabasco.
Vicky