Goat cheese is a light, tangy, fresh cheese made with goat milk, and it has an unmistakable gamey flavor that adds sourness to fatty, salty mashed potatoes.
In Garten's recipe for goat cheese mashed potatoes, she adds around 7 to 8 ounces of herbed goat cheese to 3 pounds of boiled Yukon Gold mashed potatoes.
The goat cheese is for flavoring, so you'll still need milk and butter. Garten also uses a little sour cream to enhance the tangy flavor of the cheese and add a creamy texture.