In the top of a double boiler add the milk and onion; heat until it begins to simmer, but don’t let it come to a full boil.

Rub together the butter and flour to make a paste.

Add the paste to the milk mixture while stirring.

Add the grated turnips and salt, and cook while you continue stirring until the turnips are soft, about 10-12 minutes.

Just before serving, remove the onion and stir in the parsley.