Company Breakfast Casserole

From: Gooseberry Patch's Christmas Kitchen
Submitted by: Jena Buckler from Bloomington Springs, TN  
16-oz. pkg. frozen shredded hashbrowns, thawed
1 onion, chopped and divided
1 lb. ground pork sausage, browned and drained
1 green pepper, chopped
4-oz. can sliced mushrooms, drained
1/2 to 1 c. shredded Cheddar cheese
1 doz. eggs, beaten
1-1/2 c. milk
salt and pepper to taste
Optional: garlic salt to taste 

Spread hashbrowns in a lightly greased 9"x9" baking pan. Layer ingredients as follows: half the onion, sausage, remaining onion, green pepper, mushrooms and cheese. In a separate bowl, mix together eggs, milk and seasonings. Pour egg mixture over top of casserole; cover with aluminum foil and refrigerate overnight. In the morning, bake, covered, at 350 degrees for 45 to 60 minutes. Uncover and bake an additional 15 minutes, or until golden and a knife inserted in center comes out clean. Serves 8 to 10.