"My local BIR which i've eaten from for 25 plus years always manages to have a wonderful tomatoey taste to their vindaloo. However, this isn't overpowering and there is no way it is achieved by tomato paste / blended tomatoes alone. It has a unique flavour which i've never experienced in any other restaurant. It can only come from one of two things I believe. More on this when i have had time to experiment a little."
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I know that some restaurants and TA's use other more unusual 'condiments' in their cooking to obtain a more unique taste and to differ from other establishments. These condiments have not been mentioned in any video I've seen although it might have been mentioned before in this forum. For example, some places use Maggi liquid seasoning on their tandoori dishes and Maggi stock cubes in their curries. I've used them bore myself and they have a very distinct flavour which I have detected in some places.