1 1/4 lb Yukon Gold potatoes (about 4 medium), left unpeeled and cut into 1-inch pieces
1/4 c low-fat buttermilk
1/4 c nonfat milk
2 T parmesan cheese
Salt to taste
2 tsp butter, cut into 4 pieces (optional)
Place potatoes in a steamer basket fitted over a large pot of boiling water. Cover and steam until the potatoes are knife-tender, 12-15 minutes.
While potatoes are cooking, combine the buttermilk and regular milk in a small saucepan and cook over the lowest possible heat until just warm. Be careful not to let it boil or the milk will curdle.
Drain the potatoes, return them to their pot, add the warmed milk, and mash together to the consistency you prefer. Stir in the Parmesan cheese and season with salt. If desired, serve with a dab of butter on top.
I added more cheese and milk to ours!