Do yoh mean for eating out or buying in? In and around dulwich the places i know are The dish and the spoon in nunhead for gf cakes and main meals, soup salad with himemade gluten free bread. Ganapati in peckham is an Indian restaurant and takeaway with plenty of gluten free options, brockleys rock do gluten free fish and chips on a tuesday, Maddies fish bar in New cross do gluten free batter. Im sure theres plenty more too!