2½ lbs. (1-inch) cubed baking potato, peeled if desired
1/2 cup grated Parmigiano-Reggiano cheese
1/2 cup 2% reduced-fat milk
1/4 cup reduced-fat sour cream
2 tablespoons unsalted butter
1 teaspoon white truffle oil, or more to taste
1/2 teaspoon salt
1/4 teaspoon freshly ground black pepper, or more to taste
Place potato in a medium saucepan; cover with water. Bring to a boil. Reduce heat, and simmer 20 minutes or until tender. Drain. Return potato to pan; add cheese and remaining ingredients. Beat with a mixer at medium speed until smooth, or mash with a potato masher until desired consistency.
--Adapted from Cooking Light