Easy, Cheesy Brunch Casserole
["4 slices bread", "1 medium onion, chopped", "1 c. sliced mushrooms", "2 Tbsp. margarine", "1 c. chopped ham or 1 lb. sausage", "1 c. (4 oz.) shredded Cheddar cheese", "1 c. (4 oz.) Swiss cheese", "1 Tbsp. flour", "1 1/2 c. milk", "4 large eggs, beaten", "1 Tbsp. prepared mustard", "1/2 tsp. garlic salt"]
["Put the bread in bottom of dish.", "Saute onion and mushrooms in margarine and pour over bread.", "Mix the sausage, cheeses and flour together; sprinkle on top of meat.", "Mix the remaining ingredients; pour over mixture.", "Cover and chill.", "Eight hours later, remove from refrigerator and let stand 30 minutes.", "Bake at 375\u00b0 for 35 minutes or until set.", "Let stand 10 minutes and serve."]
["bread", "onion", "mushrooms", "margarine", "ham", "Cheddar cheese", "Swiss cheese", "flour", "milk", "eggs", "mustard", "garlic salt"]