How do You pronounce the word 'niche'

[MatrosRx]

I had never heard it pronounced 'nitch' before I watched a US show that used niche in it's dialogue. It made me stop and go "Wait what? Oh, they meant niche (pronounced like quiche)..." I was just under the impression that actors just mispronounced it on purpose as an in joke because it was that kind of a comedy, but thanks to this thread, I now realise Americans just pronounce it differently to every other English speaking country. You guys seem to like doing things different just for the sake of it :P