My favourite way of serving parsnip at Christmas and really easy to make as well.
75ml double cream
salt & pepper to season
Chop the parsnips into dice sized chunks (as even as possable).
Melt the butter is a pan and add the parsnips and the salt & pepper. Sweat the parsnips for around 10-15 mins until they can be squashed with a fork.
Add the cream and bring to the boil, then transfer to a food mixer and blitz until you have a smooth pureè.