1. Roast the sweet potatoes at 400 degrees F for about one hour depending on the size of the potatoes.
2. Place the rest of the ingredients in a saucepan, stirring to blend and heat thoroughly.
3. Spoon out the sweet potato from the skins into a large bowl.
4. Add the hot liquid to the potatoes and whip together.
5. Serve immediately, or place in a casserole to be reheated and served later.