Preheat over to 375 degree F
Wash and prick potatoes with a fork several times and place on baking sheet.
Place the sweet potatoes in oven and bake for 45 minutes or until you can prick easily with a fork.
Let cool slightly.
Peel sweet potatoes and add to blender or food processor. Add the thyme and puree until smooth, adding liquid in 1/4 cup increments until you reach your desired consistency.