Preheat oven to 350 degrees
In a large bowl, add ground turkey, Worcestershire sauce, onion, mayonnaise, breadcrumbs, salt, pepper, 1 tbsp ketchup, and, if choosing to do so, bell pepper and celery.
With your hand, mix just enough to evenly incorporate all the ingredients. Do not overmix or the end result will be tough.
Press mixture into a 9x5 inch loaf pan and place into the oven. Cook for approximately 30 minutes or until the internal temperature has reached about 150 degrees.
Remove from the oven and cover the top of the meatloaf with an even layer of ketchup. Place back into the oven and cook for another 15 minutes or so, until the internal temperature has reached 165 degrees.
Remove, let rest, then slice and serve with your choice of sides.
