The food is best experienced as a Mexican take on tapas. The dishes are uniformly delicious, vibrant in both appearance and taste, fresh and (just about) seasonal. However, they can be a little heavy on the chilli in some cases. If you don't finish your meal with the chocolate and churros then you are missing out on a sublime treat.
There are outlets in Covent Garden, Westfield in Shepherd's Bush and apparently one will be opening in Canary Wharf soon. I'm looking forward to some lunchtime treats!