Yukon golds make brilliant mashed potatoes, thanks to their balance of waxiness and starch. Because yellow potatoes are more flavorful than others, they don't need a lot of fat to taste rich. Mash them by hand just until creamy--overworking the potatoes will make them gummy.
Place potato in a saucepan; cover with water. Bring to a boil; cover, reduce heat, and simmer 10 minutes or until tender. Drain. Return potato to pan. Add milk and remaining ingredients; mash with a potato masher to desired consistency.