Root Vegetable Gratin

Ingredients

• 1 1/2 cups (6 ounces) shredded reduced-fat Jarlsberg or Swiss cheese
• 2 tablespoons minced fresh onion
• 1 tablespoon prepared horseradish
• 2 garlic cloves, minced
• 4 cups (1/4-inch) sliced peeled Yukon gold potato
• Cooking spray
• 1 3/4 cups (1/4-inch) sliced peeled parsnip
• 2 1/2 cups shredded peeled celeriac (celery root)
• 1/4 teaspoon salt
• 1/4 teaspoon black pepper
• 1/2 cup fat-free, less-sodium chicken broth
• 2 tablespoons dry breadcrumbs
• 1 1/2 tablespoons butter or stick margarine, melted