because I didn't get to read your responses on time, I advanced with the following measures:
250g of rice (about a medium-small mug - heaped)
2.5 cups of water (the amount didn't matter in my case, as I don't cook with reduction method, see my pilau rice recipe)
1 chef spoon of fresh milk
I thought the rice texture improved slightly, but the rice felt slightly stickier than my usual. I'm not too sure if that made a difference, but next time I'll do 50:50. The biryani came out nice, although not as savoury as the biryani from a TA/BIR.