Cheesy Potato Casserole

Boil a substantial amount of salted water in a large vessel until it reaches a rolling boil. Cook diced potatoes in the boiling water until they become soft and palatable, typically taking between 8 to 10 minutes. Subsequently store the cooked potatoes in the refrigerator for an extended period, preferably overnight or for at least 8 hours.

Preheat your oven to a high temperature of 350 degrees Fahrenheit (or the equivalent temperature in degrees Celsius). Grease a standard-sized 9x13-inch baking dish with a suitable cooking spray.

Grate the cooked potatoes into a large container. In a separate, smaller bowl, combine melted butter with finely chopped onion, fresh parsley, salt, and pepper. In yet another small bowl, mix together sour cream with milk.

Arrange half of the potatoes in the bottom of the prepared casserole dish. Sprinkle with half of the butter-spice mixture, followed by half of the sour cream-milk mixture. Cover with a layer of processed cheese, approximately 1/2 cup in quantity. Repeat the layering process with the remaining ingredients.

Bake the assembled dish in the preheated oven for a period of 1 hour.