I have a recipe for duck with sweetened chestnut puree but I have only unsweetened in my cupboard. Does anyone have an idea how I can pimp the unsweetened?
I would add a little agave syrup or honey to give it some sweetness
It also depends on what kind of flavor profile you are after. If you want puree to be "pure" and not to much flavor added to it, you could add appropriate amount of confectioners sugar or simple syrup.