Make Ahead Mashed Potato Casserole Recipe

Ingredients

• Potato Ingredients
• 5 pounds russet potatoes, peeled and cut into 1 inch cubes
• 4 garlic cloves (optional)
• 2 shallots, minced (optional)
• Kosher salt - 2 teaspoons, one at a time and taste
• Freshly Ground pepper, to taste
• 1 1/2 stick butter (12 - tablespoons), cubed and slightly softened
• 1 cup (8 ounces) sour cream
• 3/4 to 1 cup warm heavy cream
• Topping
• 1 cup Panko bread crumbs
• 1 cup parmesan cheese
• 5 tablespoons butter