Preheat oven to 350 degrees.
Spray a loaf pan with nonstick baking spray. Cut the crust off the bread.
Once the crust has been removed, shred the slices of bread into small pieces.
Put the ground sirloin, bread crumbs, chopped onion, egg whites, ketchup, mustard, salt and pepper in a large bowl.
Mix all of the ingredients together.
Make the blended ingredients into a loaf. Put the loaf into the prepared loaf pan. Set aside.
Add the sauce ingredients in a small bowl. Whisk the ingredients together.
With a kitchen brush, evenly coat the top of the meatloaf with the sauce.
Transfer the meatloaf into the oven. Bake at 350 degrees for 55 minutes.
Remove from the oven and make sure that the meatloaf is completely cooked. If not, return to the oven.
If it is completely baked, take it out of the oven. Set the loaf pan on a cooling rack to cool for 10 minutes.
Slice into 5 servings.
Enjoy!