Had to give it a go ;D: my base has turned out a bit more orangey than Julian's as I put some passata in, not having a tin of diced tomatoes handy. I marinated some chicken overnight and currently precooking it Julian's method, and I'll whip up a Madras tonight.

I'm not limited to AIR cooking as I made up a big batch of Chorley style dry mix and his Garam Masala some time ago.
One thing that does impress me is that I've clearly ended up with enough base for four or more single portions, and that's not including the chefs spoon I put in the chicken precooking pan.
So for a quick BIR style gravy that can be knocked up in 20 minutes then put away for a few curry nights (SWMBO doesn't like curry much except for the odd no-chili butter chicken) it seems like a great compromise with cooking up a massive pot of base.
On another point, the liquid that I drain off the precooked chicken, can that be used ladle for ladle as "chicken stock" or would it be a bit spicy and possibly "over egg the pudding"?
Edit: another thing that you can probably see in the photo, I got a really nice oil "break" in the gravy which would have taken me a lot longer using the "trad" method.