My daughter is a teacher who's lived in London for four years....I'm not sure if she'd have been able to thrive and prosper there without her weekly Saturday trek to Borough market. London Bridge tube...not too far from where you'll be. You can just nosh your way through the market, or stop somewhere and chow down.

My personal favorite here is the section with the cheese vendors....plenty of free samples. But its all good, and has been pointed out, there are also several good/inexpensive restaurants (and pubs) nearby.

When we go over to see our daughter, the market serves us as sort of a "moving brunch" on Saturdays. And then we usually make another meal or two from some of our purchases. Usually a wine & cheese sort of thing that makes for a nice alternative to a pricey restaurant meal.