Three Potato Gratin

Ingredients

• 1 tablespoon unsalted butter
• 2 heads garlic, halved
• 1 quart cream
• 1 pound peeled white potatoes, 1/4-inch slices
• 1 pound peeled sweet potatoes, 1/4-inch slices
• 1 pound red potatoes, 1/4-inch slices
• 2 cups grated Parmigiano-Reggiano, plus 2 tablespoons for garnish
• Salt and white pepper
• Essence, recipe follows
• 2 tablespoons chopped chives
• 2 1/2 tablespoons paprika
• 2 tablespoons salt
• 2 tablespoons garlic powder
• 1 tablespoon black pepper
• 1 tablespoon onion powder
• 1 tablespoon cayenne pepper
• 1 tablespoon dried leaf oregano
• 1 tablespoon dried thyme