You may prepare this biryani in oven as well instead of going for slow cooking on stove top. Follow the recipe till rice and vegetables are cooked. Then assemble/layer them in an Oven proof dish in the same manner as described above.
Cover it with a foil tightly with no loose end, and then place a heavy oven safe lid on top (or a ceramic plate would do too). Cook it in a preheated oven for 30-35 minutes at 180 degrees and serve.
You could also squeeze some lemon juice once the biryani is cooked and keep it covered till you start serving.
I usually use a ratio of 1:1.5 cups for rice and water, so have given the measures accordingly. But you may use the measurement according to the variety of basmati rice you use.
Always use a heavy bottom pan or pot for slow cooking the biryani so it doesn’t get burnt or stick at the bottom. I used a my 5 ltr pressure cooker and covered it with a thick kitchen towel, and then placed a ceramic plate, and lastly a filled sauce pan on top.
To serve in style, you may assemble and layer the biryani in small ramekins individually and then keep them all in oven. Take them out after 20-25 minutes, open and serve fresh with chilled raita