Great looking nans, though if you don't have all the kit i.e. a tandoor et al, I find that pre heating a heavy based frying pan or griddle and at the same time pre heating the grill.  Drop the nan on the frying pan and when the blisters start to appear get the pan and pop it under the grill, the top of the bread puffs up a treat, I suppose it sort of replicates the conditions found inside the tandoor, with direct heat contacing the back of the bread and high radiated heat acting on the top of the bread, go on try it you'll like it  ;D