2 pounds potatoes, peeled and quartered
2 ounces butter, unsalted, room temperature
1/3 cup heavy cream
1/4 cup sour cream
4 ounces white Cheddar cheese, grated
1 teaspoon salt
1/2 teaspoon white pepper

Place potatoes in pot and cover with cold water. Bring to a boil and simmer until fork tender. Drain completely.

Mix potatoes with an electric mixer until smooth. When smooth, add butter and blend. Add cream, a little at a time and beat; add sour cream and blend. Add cheese, salt and pepper and blend again.