Masala dosa is food of the gods as far as I am concerned. After a year in India it was pretty clear that most of what is served here is nothing like what you would eat in India. The street food is incredible, even something as simple as "bombay mix" in Calcutta is transformed by the addition of tomato, onion, chilli and coriander.
Whilst Dishoom is ok, my go to Indian cookbook is Sanjeev Kapoor, Mastering the Art of Indian Cookery. Any recipe I have ever followed in that book is delicious.
I have also spent a fair amount of time in China and had a lot of formal banquets, I really did not get on with the food of Shanghai but I was OK with Cantonese food in Hong Kong.
I rarely eat in Indian or Chinese restaurants in the UK and never ever have takeaways. I will happily eat in a dabha style cafe in Southall or in a South Indian place that does dosas but the high street places - nah.