This is my favorite place in London. The Café opened 5 or 6 years ago and I remember when there was just Rob (the owner) and couple of other guys serving coffee from a machine placed on a timber temporary desk with no kitchen. A lot has changed since then and now this place is a fully functional café serving organic breakfast and lunch with terrace overlooking the pond. You could also buy in there organic bread and cakes from their own bakery as well as hot and cold drinks like locally sourced beers and ciders.
I can't explain why but I can actually relax there, slow down the time, read a book or look at the water and simple life of the birds and forget for the moment about the speed of a London's life.