Interesting but I'm not buying into the Ghee improving my currys thing, ok it has it's place in some dishes. But after many times of buying ghee and using it in base it's ok but I preference veg oil. As a poster mentioned above, ghee solidifies when cold! And I have never seen a TA curry solidify in my fridge, and it's not something I want to see.
Ok it has it's please in sweeter richer dishes were it can be hidden.
I believe a lot of TA are more inline with health these days and also use veg oil as standard, most customers no longer want to see oily food !
TA and BIR want customers bums on seats, also a healthy profit when they return time and time again.