If you think that your dal fry has too much water (hydrated), then there is no way to reduce the water from there. So at that time the gas should be brought to a medium level and boiled for a while more. Stir a little from time to time, if you stir too much, all the lentils can melt. keep boiled until the extra water evaporated.
This is the only process to dehydrate cooked Dal Fry.