Peel potatoes, cut into large, equal-sized chunks and place in pot with water to cover. Bring to boil and cook until potatoes are fork-tender, 12-18 minutes. Drain well, then cover pot and heat potatoes over low flame, shaking pot occasionally, until potatoes look dry, 2-3 minutes.

Pass potato chunks through a potato ricer into a large bowl or mash them on low speed with electric beaters. Fold in softened butter, milk and salt and pepper to taste (remember you’ll also be adding cheese, so go easy on the salt). Let cool to barely warm or room temperature.

Heat oven to 400 degrees. Butter a medium baking dish. Beat egg yolks and stir them into the potato with cheese and chives. Using electric beaters and a clean bowl, whip egg whites until stiff peaks form. Use a large rubber spatula to fold a quarter of them into the potatoes, then gently fold in the rest. Transfer potato mixture to baking dish, using spatula to create a few decorative peaks. Bake until top is brown-tipped and potatoes are heated through, 25-30 minutes. Makes 4 servings.