How to Make It
Bring onion and celery root to a boil in a large Dutch oven filled with water. Reduce heat, and simmer 15 minutes or until tender. Add beans; cook 2 minutes. Drain. Place half of celery root mixture and 2 tablespoons milk in a blender; blend until smooth. Return puree to pan. Repeat procedure with remaining half of celery root mixture and remaining 2 tablespoons milk. Stir in sour cream, butter, salt, 1 1/2 teaspoons juice, and cheese.
Combine rind, remaining 1 tablespoon juice, almonds, and mint in a bowl. Spoon puree into a serving dish; sprinkle with almond mixture and celery leaves, if desired.