Leila McAlister's grocery shop and café off Arnold Circus, Shoreditch. You can find the best of everything, from jars of horseradish to eggs and croissants.
Good, progressive, solid, forward-thinking place. And run by the warmest, most intelligent and inspiring people to be around. Always a humble, fulfilled visit. And whilst in the area, best to visit next door to Hannah Barry's gallery for more wonderful work.
Paul Rothe n Son has been there 120 years, bang in the middle of town. Hard to find a proper old-school deli in central London nowadays, n none more proper than this place. Great jacket potatoes, soup, sandwiches. It looks the part too. And the service is always great. Try and avoid the lunch queue.
Slightly biased as this is where I live, but Stoke Newington is great place to spend lazy saturday / sunday afternoons getting sloshed with friends. There are 10 + pubs within walking distance who all are great places for one reason or another. I'll pick out the White Hart for its huge beer garden...