Ingredients:

• One 2-pound bag frozen Idaho hash browns or diced potatoes, thawed* OR 2-1/4 lb Idaho Russet potatoes peeled, par-boiled and grated
• 3 tablespoons butter or olive oil
• 1 cup diced onion
• 3 ounces diced fresh mushrooms, about 1-1/2 cups (optional)
• 1/4 cup all-purpose flour
• 1 cup chicken or vegetable broth
• 1 cup milk
• 1/2 teaspoon salt
• 1/4 teaspoon ground black pepper
• 2 cups (16 ounces) sour cream or plain Greek-style yogurt
• 2 cups (8 ounces) shredded cheddar or Monterey Jack cheese
• 2-1/2 cups cornflakes, crushed to about 1-1/2 cups OR 3/4 cup panko crumbs
• 1/4 cup melted butter

Directions:

1. Preheat oven to 375°
2. Place potatoes in a large mixing bowl or 9x13-inch baking dish.
3. Melt butter in a wide skillet over medium-high heat. Add onions and sauté until softened.
4. Stir in mushrooms if desired; cook stirring occasionally until mushrooms are cooked.
5. Stir in flour until moistened. Add broth, milk, salt and pepper. Stir constantly until mixture comes to a boil; stir 2 minutes until slightly thickened. Remove from heat.
6. Stir in yogurt and cheese. Combine with potatoes and choice of variation ingredients if desired. Spread evenly in baking dish.
7. Sprinkle top with crumbs. Drizzle with butter. (Dish can be refrigerated up to 2 days before baking). Cover with foil and bake 45-60 minutes until starting to bubble at edges. Uncover and bake additional 10-15 minutes until golden brown.