Prepare the parsnips and cook them as in Parsnips—Conservatively Cooked.
Drain off any liquid left in the pan and reserve it for a soup or gravy.
Mash with a fork or rub through a nylon sieve.
Heat the butter or margarine in a pan and beat in the puree, add the milk, stir over heat until thoroughly hot.
Serve in a hot vegetable dish and sprinkle with chopped parsley.