London is a diverse city with a diverse food culture. 'Traditional British' is standard heavy pub fare, with shepherd's pie, fish and chips and beer high on the menu, genuine Londoners are just as likely to be found downing Indian curries on Brick Lane and East Asian noodle soups. London is a great place for all tastes and budgets to eat out.
Nightlife is similarly varied across the city. Although pub culture is a big part of British life and definitely worth experiencing, there's no shortage of bars and clubs either, with each neighbourhood of London offering a different experience - Central London offers the glitz and glamour, Camden has a more relaxed vibe and draws big student crowds, and areas like Peckham and Dalston have undergone huge regeneration in recent years and now offer the best in cutting edge dance music. Whatever your tastes, you'll soon find your new favourite nightspot on the streets of London.
Very few Kosher items are sold in central London. Waitrose has a very small section for cold cuts and refrigerated/frozen foods, but is very limited. The best area to go is to Golders Green in Zone 3.
Halal food is a lot more common, both in supermarkets and restaurants. Some branches of fast food chains are also halal-only.
You pay a different tax if you sit down to eat at a restaurant than if you order take-out.
London is very vegetarian and vegan friendly: most restauraunts will have at least one option, marked with a (v) on the menu, and supermarkets also display this information on their products.
For information on where you can find vegetarian and vegan friendly selections, visit Happy Cow.