This recipe comes from another Kindergarten teacher in my school. These are out of this world delicious and great with steaks or a prime rib dinner. If you need to, you can substitute cream cheese for the mascarpone.
Place potatoes in a large pot and cover with water. Bring to a boil over medium-high heat and simmer until the potatoes are tender, 20-30 minutes. Drain thoroughly and return them to the pot in which they were cooked. Return to the heat briefly to evaporate any excess water that may still be clinging to the potatoes.
Using a hand-held electric mixer, beat the Mascarpone cheese and butter into the potatoes until thoroughly incorporated and fluffy. Beat in the chives or scallions and season with salt and pepper.
Transfer the potatoes to a shallow 1 1/2 to 2-quart gratin dish. Sprinkle the Parmesan over the top and then dust evenly with paprika. Cover the potatoes with plastic wrap and refrigerate for UP TO 48 hours before heating.
When ready to heat the potatoes, bring them to room temperature and preheat oven to 350°F Bake the potatoes until hot, puffed, and light brown on top, about 30 minutes. Serve at once.