...I have been using the Dhillon base and it's pretty good but not quite there I think. I saw somehwere that someone added a little sugar and lemon juice to this and it was said to be even better.
But how can you know how good any DIY base sauce really is? I suggest there are only two methods of assessing it:
(a) If you have a control sample of a genuine BIR base sauce at home, and can compare your base sauce with that, or
(b) if it results in a really good curry at the end of the day, after you've added lots more ingredients at 'stage 2'.
I made a superb base sauce from this forum, thanks to markJ., It tasted so good, you could consume it like a fine soup. But that's not the point really. It's only as good as the curries it will produce.
Regards
George