Laws of Shabbat - 16

Two pots are on the fire and the food in them is cooked completely - It is permitted to move the food from one pot to the other. Therefore, if you see that the cooked food is in a covered pot on the fire, and it becomes dry, then one is permitted to moisten it from the boiling water than comes from an urn or a kettle sitting on the fire. It is also permitted to move water from the kettle using a spoon or a ladle and putting it on the cooked food, on a closed fire, on the condition that the spoon or ladle is clean and dry before use.