Parsnips are in the same family as carrots and parsley. Before the introduction of potatoes from the New World, parsnips were an important staple crop in Europe with the variety grown today having been developed in the Middle Ages. 
Like potatoes or carrots, parsnips do well roasted. Peeling the skin can make them a little less bitter, but we usually don’t bother. Parsnip puree is another classic preparation.