1-2 pounds celery root

1-2 pounds potatoes 

1 cup milk and/or cream

4 oz butter

Salt and pepper

Most recipes for celery root-potato puree call for anywhere from equal parts (by weight) potatoes (russets or gold potatoes like the Weiser satinas) to 2 part potatoes to 1 part celery root. 

Peel potatoes and celery root. Cut potatoes into ½ inch dice and celery root into 1 inch dice. (The celery root cooks faster.) Add to pot and cover with cold water and a couple teaspoons of salt. Bring to a boil and then reduce heat and simmer until very tender. Drain and dry. Heat 1 cup of milk and cream in any combination (½ cup milk and ½ cup cream or all cream or milk). Pass potatoes and celeriac through a rice or food mill or mash it with the butter. (The fat coats the starches and prevents it from getting gummy.) Once all the vegetable is pureed, stir in the milk/cream. Adjust seasoning.