The incidence of ethnic restaurants in Oxford can be no coincidence and is to a degree matched by Cambridge, though with nothing like the same intensity. Does this indicate a better standard of in-house catering in the Fenland bastion - I doubt it. So here we are again, but this time with probably the best of the bunch amidst the dreaming spires. To have a Thai restaurant within a fourteenth century building just off the High in Oxford seems slightly odd until you remember the difference between our two civilisations. And theirs has produced a cuisine which over the last few years has taken Britain by storm. Here the cooking is hailed as superb and the concensus of opinion seems to be that of the many eating houses in Oxford, Chaing Mai is more on its way than most.