Couple of places nearer to home and not in West Peckham -

1) I don't know if it's still there, but there used to be a good Iranian grocery on Sydenham High Street, selling stuff like pomegranate concentrate and harissa

2) The Thai mini-mart in Crofton Park

Recipe (ish)

Cous Cous is really quick, and very tasty if (once it's done) you chuck in some toasted pine nuts, chopped up tomatoes and herbs/chopped french beans or such-like, then dress with lemon juice and olive oil. Has the advantage of partially hiding veggies (or at least looking prettier than a portion of boiled broccoli) if you have kids who turn up their noses at such things. Can be made while grilling some fish or lamb or chicken, for a nice meal taking less than 20 minutes.

I'm also attempting to grow my own veg. Can recommend Perpetual Spinach (Spinach Beet). You can cut leaves off regularly, and unlike true spinach, it doesn't 'bolt'. The stuff I planted last summer is still going - unhindered even by the snow! Pak Choi also does well.
Word of warning: get some bird netting - not so much against birds, but squirrels.

Good book for a novice gardener:

The Gardening Which? Guide to Growing Your Own Vegetables by Liz Dobbs, ISBN 0-85202-834-2

Loads of useful info in digestable form on veg and herbs from A-Z, with good stuff on best varieties to grow, loads of ideas for things like making good use of space and avoiding diseases. Also has info on how to store, including how to freeze vegetables from your garden properly.

Good luck!