Peel the turnips and cut them into large, even pieces.
Put the turnip pieces into a pot with water and some salt. Bring to a boil and cook on medium until they are easily pierced with a fork, about 10-15 minutes.
Drain the turnips and let them sit in the pot for a few minutes, so steam can escape.
Add some milk, starting with 1/4 cup, and mash. Add more milk until you like the consistency. Add salt as needed.