I've tried, gently, to suggest that the chefs are witholding or deliberately changing something in the base recipe, for some time, but ha ha or I don't speak good English usually crop up somewhere.
I too would relish the experience of a trip to a restaurant / takeaway kitchen, but we do not want to be conned. We need to see a dish cooked from base to conclusion, so we know that EVERYTHING is being disclosed. I know that time wise this is impossible in one evening, so, as I believe that the mystery is in the base sauce, I think that buying a base sauce from our locals and using our gained knowledge to complete the various dishes will confirm this, we should try this as our next step of elimination. I personally have tried to buy base sauces from my locals (one of which I have used for almost 20 years) and they will not sell it to me. To this end I will be out this weekend, and buy a base from anywhere that will sell me one, just to see if this is where "the taste" is and then we have narrowed our search.
I hope that this post makes some sense as I have the weekend off and have had a little bit of wine,
cheers all,
Blondie