Bacon and Potato Egg Casserole

°1/2 lb bacon, chopped
°1 onion, chopped (1/2 cup)
°1 bag (30 oz) grated and frozen hash potatoes, thawed, sponged
°2 cups cheddar cheese (8 oz)
°1/4 cup grated Parmesan cheese
°9 large eggs
°1 1/4 cup milk
°1 container (8 oz) sour cream
°1 teaspoon salt
°1 tsp ground mustard
°1/4 tsp pepper
°1/2 cup cornflake or panko breadcrumbs
°2 tablespoons butter or margarine, melted

Heat oven to 350°F. Spray 13-9-inch (3-quart) glass baking dish with cooking spray.
In 10-inch skillet, cooking bacon and onion on medium-high heat for 10 minutes, Stir occasionally, until bacon is crisp also onion is tender; draining on paper towel. 
In a large bowl, combine the bacon mixture, potatoes and cheeses. Pour into an ovenproof dish. In the same bowl, beat the eggs, milk, sour cream, salt, mustard and pepper with a fork or whisk until smooth. Pour over potato mixture.

Bake uncovered for 35 minutes. In a small bowl, combine the cornflake crumbs and butter. Sprinkle over the pan. Bake for another 10 to 15 minutes