Hi BB,
He is a very famous Indian Chef, also works with or for Sanjeev Kapoor I think who again is another very famous Indian Chef, lots of vids available from both.
The series below looked like a restaurant style teaching course, training up coming chefs. They make a couple of dishes from them too, not sure if you've seen those vids.
You can see perhaps from these how the AIR type developed, somethings a little different. Ie, no fresh tomatoes used here, tomato paste as there is no time to do all that.
The yellow gravy is very similar to a Yellow Gravy that is used at a Punjabi restaurant that I have been in the kitchen for as well, except he (Brisbane Chef) doesn't add nuts to it. He does that so that he can serve to people who have allergies and adds later if the dish needs it. He also doesn't blend it fully but keeps some texture in it so that when added to a dish it gives more body to the sauce.
For a Lamb Vindaloo for example :
1 chef spoon Yellow Gravy
2 chef spoon Lamb Gravy with Lamb Pieces(this is actually a gravy with the Lamb cooked in it, same happens for Beef, similar to JJ, quite thick)
1/4 - 1/2 chef spoon Vindaloo Paste - this is store bought from All India Foods, Lashand Brand and is supurb, can only get it 5 kg tubs though! I'm thinking of getting one it's that good. Would use with JJ's Master Gravy and add to it.
Bit of hot water is added and salt if required.
Cheers,
Mark