This is not true. I have achieved 'the taste', and reporduced perfect imiatation takeaway dishes 3 times now. I've made curry every night for the last month (really), with the quest of hitting the nail on the head. I've done it three times - what I can't do is reliably reproduce it. As a result, I'm unable (so far) to? identify exactly what it was bout what I did one time that wa right, and what was not etc.
I chop 3-4 onions very finley - some finely dived, some finley sliced into small strips. I fry these gently in plenty of oil, with a bit of base sauce, and a desert spoon of *cinnamon* on them. I slowly fry them for 30-40 minutes, until they are totally soft, see through, and sweet.
At the end of last year I made four brilliant vindaloo curries which I knew to be as good as I ever would get.
Everyone who tried them said the same.
They had the "eat every last bit of it" flavour.
Almost the same as a restaurant but fresher.
And................I don't know what I did right.
I am currently backtracking to try and do it again.
When I do, I will post it.
One of the problems is that I try too many different things.
I get enthusiastic whenever I see an interesting post, or if I chat with a chef.
I have read several post regarding adding pre fried onions.
So I started adding them to my curries as a matter of course.
They only improve it.
Here I go experimenting again..........
What about making the 600ml oil base but cook the onions in more oil for an hour, then add the water and other ingredients.
One thing seems clear to me, is that when we achieve the taste, it will not be through the standard methods used in a takeaway.