A very interesting video Pap, but I'm not sure what you mean about the comments about Base Gravy. All he said was you're making the base gravy and curry at the same time and I couldn't find anything in the comments. Looked like a 3 hour cook at least to me.
The things I saw.
First of all it is rare to see a really good "Beef" curry. I'll be doing this for that reason alone. It looks great.
Was it pink salt or black salt (which is pink)?
I love the way he keeps saying "Don't worry about the oil and fat." As he demonstrates and makes very clear it can be removed. Although he doesn't actually say it, this is often a criticism of Base Gravy / BIR method. The oil is blended / emulsified into the dish (ie hidden).
Chilli. He is using Kashmiri Chilli. Mild. (supposedly) Interesting to note that 1 or 2 or 3 teaspoons is the difference between a curry, a Madras and a Vindaloo, (while using a mild chilli powder). Raises my questions about Chilli type out of India and marketing.
The dry curry looks good. If I added as much water as he does I'd be inclined to reduce it back to the thicker gravy, but I'm not a UK wet gravy guy.
I'm looking forward to trying this and I'll be looking at his other videos.
Thanks for posting.