Cheesy Potatoes

Serves 50.

2 tablespoons vegetable oil
2 1/2 cups onions, chopped
1 (50 ounce) can Campbell's Condensed Cream of Mushroom Soup
8 ounces sour cream
3 cups milk (2% fat)
1 1/4 teaspoons white pepper
3 quarts processed American cheese, shredded
5 pounds frozen potatoes with skin, diced

In a large saucepot in hot oil, cook onions until lightly browned. Add soup, sour cream, milk and pepper. Heat through. Add 2 quarts of the cheese. Heat until cheese is melted. Stir in potatoes. Pour into baking pan (12 x 20 x 4 inches). Sprinkle with remaining cheese. Bake at 475 degrees F. Bake until internal temperature is 140 degrees F or higher or 15 seconds and cheese is melted and golden brown, about 5 minutes. Hold at 140 degrees F or higher. Portion using a 1/2 cup scoop.