2 pounds small new potatoes, unpeeled and quartered
2 pounds celeriac, cut into chunks
1/2 cup whipping cream
1/2 cup butter
2 teaspoons kosher salt
Bring potato, celeriac, and water to cover to a boil in a large saucepan; cover, reduce heat, and simmer 20 minutes or until tender. Drain and mash, leaving slightly lumpy. Stir in whipping cream, butter, and salt.