Don't want to hijack this thread but I'm curious: BIRs don't exclusively use tomato paste, do they? There are dishes like butterchicken or tikka masala, where you basically have to use something like passata or maybe even some tomato-onion-gravy? But I'm aware that this mostly concerns punjabi dishes.
I've seen places that keep a pot of their own passata on the stove, previously cooked up with some ginger and garlic, but I'm not convinced that adding it warm will make much difference.