1 1/2 c. diced celery root (hard)
1 c. diced Russet potatoes
1/2 tsp. minced shallots
1 1/2 tbsp. butter
Salt & pepper

Cook celery root in boiling water until tender, 15 to 20 minutes; drain. Cook potatoes until soft and drain. Saute shallots in part of butter. Add celery root, potatoes and shallots to food processor (blender). Puree. Add salt, pepper and additional butter.