The oriental one. I use it regularly and it is available over here in 800 gram bags.

I use Knorr Chicken Powder in everything, so I will not say that is a bad thing Phil.

You'll probably never get that answer Phil, considering the only listed ingredient is at the top with 66%.  Meaning the remaining 34% is made up the other ingredients, supposedly in decreasing order of proportionality. 

Salt could be either side of 25%. 

Palm fat is palm oil, which is somewhat controversial, but I seriously doubt it will kill you very fast.  While there are some questions on health, the main issues with it appears to be ecological or related to human rights.

The scientific names of the other ingredients (flavour enhancers, etc.) can be off-putting, but many of these are naturally occurring anyway, or derived from natural sources.  Monosodium and disodium are self-explanatory. E621, E627 and E631 on the food additives list.

In reading that list of substances, I don't see anything I would be fearful of.  However, it wouldn't be too difficult to whip up a homemade lamb stock.

As you're making stock anyway how about just adding the usual garam masala items such as cardamom, cinnamon, cloves etc. to Indian-spice the stock. Not really sure what you're after as adding anything more would make it a curry sauce rather than a gravy.

Just found this page and it looks interesting. Maybe a modified one of those gravies would suit?  https://setupmyhotel.com/hotel-staff-training/kitchen-staff-training/basic-indian-curries-and-gravy-list-standard-recipe-hotels-chef/

I found that site back in May 2020 Santa. I posted it here and it was discussed a little at the time.

https://curry-recipes.co.uk/curry/index.php?topic=15479.msg137266#msg137266

It was around the time Romain from Glebe Kitchen was doing his "Hotel Style" stuff as well.

The biggest problem I found with "Hotel Style" mother gravies was that you can find recipes for the actual gravies, but not for the dishes that use them.  Although, I did use the white gravy to make best White Chicken Korma I've ever achieved.

As you're making stock anyway how about just adding the usual garam masala items such as cardamom, cinnamon, cloves etc. to Indian-spice the stock. Not really sure what you're after as adding anything more would make it a curry sauce rather than a gravy.

Just found this page and it looks interesting. Maybe a modified one of those gravies would suit?  https://setupmyhotel.com/hotel-staff-training/kitchen-staff-training/basic-indian-curries-and-gravy-list-standard-recipe-hotels-chef/

Thanks for that link. Looks promising.
I had found a basic paste recipe to stir into the crispy bits in the roasting pans to quickly cook off before adding chicken stock and thickening.
I don’t want anything too strongly spiced, just a chicken gravy with a hint of spice to complement the chicken and potatoes.