Homemade Runza Casserole

Any of you mid-westerners are probably familiar with the infamous Runza sandwich.  I've spent some time trying to figure out how to make them at home, but could never keep the bread from breaking when I put the filling in.  I posted my recipe on Pinterest about a year ago, and thanks to this blog, I can now post a more friendly version of it!  

What you'll need:
4lbs of hamburger
1 32oz jar of sauerkraut
1 large onion or two medium onions
4 cups of shredded cheese
2 cans of mushrooms (optional)
1 loaf of frozen bread dough
1 egg, beaten

Thaw loaf of bread according to instructions - but instead of putting it in a loaf pan, put it in a bowl. Spray the bowl with non-stick spray or coat the loaf in olive oil once it's begun to thaw to prevent sticking. Allow the bread to rise. Once the bread is thawed and risen, then roll it out on a floured surface so that it is big enough to cover a 13x9 casserole/baking dish.

Brown hamburger in skillet and drain. Salt and pepper the hamburger to taste. While the hamburger is draining, put the saurkraut and onions into the skillet to sautee. Return the hamburger to the skillet with the sauerkraut and onions and mix together evenly.

Place the hamburger mixture into the 13x9 casserole/baking dish and top with the shredded cheese. You can use any cheese you prefer. You could use american cheese slices instead of shredded cheese (however, I've never tried this). Place the rolled out dough over the mixture and make sure the edges are slightly tucked around the sides of the dish. Brush the beaten egg over the bread with a pastry brush. Bake in the oven at 350 degrees for about 45 minutes, checking every so often to make sure that the crust is not burning. Serve, and enjoy!