Place potatoes in a large saucepan and cover with water. Bring to a boil, reduce heat and cook until tender, about 10 minutes.
While potatoes are cooking place buttermilk and milk into a small saucepan
and cook over a very low heat until just warm. Be careful not to boil or milk will curdle
the potatoes, add the warmed milk and mash
together to desired consistency. Stir in cheese
and salt. Top with the butter and let it melt