Celery Root, Kohlrabi, And Apple Purée

• 2 pounds celery root (celeriac), peeled, cut into 3/4" cubes
• Kosher salt
• 1 1/2 pounds kohlrabi, peeled, cut into 1/2" cubes
• 1 pound russet potatoes, peeled, cut into 1" cubes
• 1 Granny Smith apple (1/2 pound), peeled, cored, cut into 1" cubes
• 2 tablespoons (1/4 stick) unsalted butter
• Freshly ground black pepper
• Fresh chervil sprigs
• A potato ricer or food mill

1. Add celery root to a large pot of boiling salted water. Reduce heat to medium-low and simmer until tender, 11-13 minutes. Using a slotted spoon, transfer celery root to a large bowl. Return water to a boil; repeat with kohlrabi, then potatoes, cooking each separately until tender, 14-16 minutes for kohlrabi and 10-12 minutes for potatoes; add to bowl with celery root.
2. Meanwhile, bring apple and 2 tablespoons water to a boil in a small saucepan. Cover and cook over medium-high heat, stirring occasionally, until apple falls apart, 6-8 minutes, adding water by tablespoonfuls if dry.
3. Working in batches, pass celery root, kohlrabi, potatoes, and apple through a potato ricer into a large bowl. Pass mixture through ricer again if a smoother texture is desired. Stir in butter. Season with salt and pepper. DO AHEAD:

celery root, kosher salt, cubes, potatoes, apple, butter, freshly ground black pepper, chervil sprigs, potato ricer

Taken from www.epicurious.com/recipes/food/views/celery-root-kohlrabi-and-apple-puree-368251 (may not work)