Yes I sometimes put potatoes in mine.
I make it with lamb mince, peas, onions, spices, bit of curry paste, add rice.
Then (wait for the pearl clutching 😁), I open a TIN of potatoes and chop them in half, then fry them in delicious indian spices before adding to the biriani.
Yes it is a double carb dish but it goes a lot further ... lovely leftovers for lunch.