Shepherdless Pie

Ingredients

• 1 1/2 cups diced peeled celeriac (celery root)
• 2 large peeled baking potatoes, chopped (about 1 1/2 pounds)
• 1/2 cup 1% low-fat milk
• 1 1/3 cups chopped peeled Granny Smith apple
• 1 1/2 tablespoons butter, divided
• 1 teaspoon salt
• 1 1/2 cups finely chopped onion
• 1 cup finely chopped carrot
• 1/2 cup finely chopped celery
• 1 cup finely chopped peeled turnip (about 1/2 pound)
• 3 1/2 cups sliced mushrooms
• 3 tablespoons chopped fresh parsley
• 1 teaspoon ground savory
• 1 teaspoon chopped fresh or 1/4 teaspoon dried thyme
• 1 tablespoon all-purpose flour
• 1/2 cup apple juice
• 3/4 cup (about 3 ounces) grated raclette or Gruyere cheese
• 1 (10-ounce) bag fresh spinach
• Cooking spray
• 2 tablespoons dry breadcrumbs