Monday nights are always curry nights at my house. On Sundays, we usually cook up a roast Sunday dinner with all the fixings, so I always make extra roast potatoes for this curry. You could do the same in place of the pre-cooked stewed potatoes used here, although the cooking stock is nice added to this sauce.
Bombay aloo can be served either quite saucy or dry, and as I usually serve this curry as a side dish, my sauce is on the dry side. If serving as a vegetarian main course, you might want to add more liquid.