This might be too late for you, but:
Ottolenghi in Islington - amazing mediterranean tapas food.
Holly Bush pub in Hampstead - used to be the best pub and best pub food in London. Still a great pub, but I've heard the food has gone downhill.
Caravan in King's Cross - great scene and great food
The Albion pub in Islington - also a great pub, and the food is still great
Borough Market - Friday lunchtime (and maybe Thursday), this is a HUGE food market near London...