I'll be in London the last week of August, working with cocktails. (I'm a food writer and spirits & cocktail professional from New York City.) I'll be staying in either the Barbican area or Islington, and working in Islington. I have one full weekend, quick lunch, and every night free; and I'm looking for cuisines that aren't that common in NYC. African especially. What can you recommend that is relatively inexpensive, and very good, that is easy to get to?