Make-Ahead Mashed Potatoes

5 pounds Yukon Gold potatoes, cubed

2 (3 ounce) packages cream cheese

8 ounces sour cream

½ cup milk

2 teaspoons onion salt

ground black pepper to taste

Preheat the oven to 325 degrees F (165 degrees C).

Place potatoes in a large pot of lightly salted water. Bring to a boil, and cook until tender, about 15 minutes. Drain, and mash.

In a large bowl, mix mashed potatoes, cream cheese, sour cream, milk, onion salt, and pepper. Transfer to a large casserole dish.

Cover, and bake for 50 minutes in the preheated oven.