This was a happy accident that resulted when I was using a combination of leftover and new potatoes to make mashed potatoes. It doesn't really taste any different but it is rather pretty. 2 white sweet potatoes 2 russet baking potatoes 1 red or orange-fleshed sweet potato butter cream or milk Salt and white pepper Peel and cook the white sweet potatoes and the russets. Make mashed potatoes with them as you usually would. Needless to say using plenty of butter and cream gives the best results, but if you must cut back it's ok, I forgive you. Meanwhile peel and cook the red sweet potato and mash it coarsely. Mix in with the fist mixture, but not completely, so the red streaks and chunks stand out against the white/yellow background.