Boil each potato variety separately in lightly salted water until just done.
Keeping the three varieties separate, run each through a food mill or ricer. Season with 1â€“2 tablespoons of butter, 2â€“3 tablespoons of cream or milk, and salt and pepper and set aside.
To assemble, place alternate scoops of each type of potato in the bottom of a wide bowl. Layer until all the potatoes are used, making sure to layer the colors so that they alternate.
Take the handle of a wooden spoon and drag it through the potatoes to get a marbled effect. If desired, drizzle with maple syrup to garnish. Serves 8â€“10.
2 pounds russet potatoes,
1/4â€“1/3 cup salted butter