Check it occasionally to make sure there is enough liquid in the pot, and if it looks dry, add some water. (inerikaskitchen.com)
Once coated, stir constantly (on med - low heat) for about 7 - 8 minutes, or until there is no more liquid in the pot. (alattefood.com)
If you think you still have too much liquid in the pot, let the sauce boil, uncovered, for a few minutes, until the liquid is reduced. (whereismyspoon.co)