Cover the sweet and Yukon gold potatoes with water and bring to a boil. Simmer for 20 minutes or until just tender. Drain the potatoes and return them to the saucepan, over low heat. With a potato masher, puree the sweet and regular potatoes with the butter or cream or broth if you are on a diet. Season to taste with salt and pepper. Here too, you can zap up the adults' portion. Remove half of the kids portion and leave it plain; add to the adults' version either grated orange zest, fresh horseradish or your own favorite seasoning.