• Preheat oven to 400℉ / 205℃. Heavily grease a 9-inch x 13-inch baking dish, set aside.
• In a large mixing bowl, combine 8-10 cups Shredded hash browns, 2 (10.5 oz) cans Condensed cream of potato soup, 1 ½ cups Sour cream, ½ cup Salted butter, melted, 2 cups Shredded cheddar cheese, 1 cup Parmesan cheese, ¼ cup Minced onion, minced, Fine sea salt. Stir well so that everything is combined.
• Pour the potato mixture into the prepared baking dish.
• Top with extra cheese, if desired. Then, cover with aluminum foil.
• Bake for 90 minutes, or until cheese is bubbly and the casserole is heated through. During the last 20 minutes of cooking time, remove the foil to let the cheese brown and crisp up a bit.

Storage & Reheat

• Leftovers keep in the fridge for about 3 to 4 days in an air-tight container. This casserole freezes well, and can be kept frozen for up to three months.
• Reheat - Place in the oven at 400 degrees Fahrenheit / 205 degrees Celsius until warmed through.