Peel and dice the potatoes.
Place the potatoes in a pot and add just enough water to keep them covered. Bring to a boil.
When the water starts boiling, add salt. Cook until tender. Drain the excess water.
Reduce the potatoes to a paste using a potato masher.
Combine milk and butter.
Stir in the parsley.
Add parmigiano cheese, stir to combine. Serve hot.