Reckon there is a lot of mileage in Rik's base Robbo. Early days, but from what I have seen so far, expect would need considerably more time/effort with a generic BIR base to get even marginal gains, if any. It has quite a depth to it. Over browning of the onions, I have found, is a mistake. As Rik states/implies in his video, they basically just need to sweat.
Yes, the basic curry looks quite good, I suppose. It is of course top notch

Haven't made a thin curry for quite some time.
Rob