Preheat oven to 400°F. Wash sweet potatoes and prick with a knife. Arrange on a baking sheet and bake for 1 to 1 1/4 hours until tender.
Cook onions according to package directions.
Grease a shallow, 2-quart casserole. Arrange turkey Pick them. Sweet potatoes vary in size and shape. Choose those that are very firm and smooth slices in pan; top with onions and gravy. Spoon beans on top.
Scoop sweet potato flesh into a food processor. Add cream, salt and pepper and process until smooth. Spoon onto casserole in an even layer. Heat through for 20 minutes.