How Indian are you?

Don't worry: this isn't going to turn into one of those Facebook quizzes that show you what sort of a car you are, what film character you identify with or how much people love you. It's just that I've become aware of an increasing number of non-native Indians (as I heard Meera Syal call them recently) - that is, people who dress, speak and behave as though were born and raised in Mumbai when actually they come from Manchester.

I mean no disrespect, of course, but I wonder about the sincerity of those pure-bred Brits who build shrines to Hindu deities, sport a bindi and favour a flowing robe. Isn't it just a bit - you know - pretentious?