What's not to like about a cheese casserole?
Spray a 2-1/2 quart casserole dish or a 9x13-inch pan with non-stick cooking spray. Layer bread, then cheese, bread then cheese ending with a cheese layer. Combine eggs, milk, mustard, onion and garlic salts. Pour over bread and cheese layers. Refrigerate 4 hours or overnight. Bake at 350°F for 1 hour. Serve immediately with fresh salsa. (Crumbled cooked bacon and chopped green chilies can be added to each layer for a nice variety of flavors.)