Preheat the oven to 350°F.
Place the beef and pork in a large mixing bowl. Add the garlic, onion, celery, and parsley, but don’t mix with the meat yet.
In a separate bowl, whisk the egg and milk together until blended. Add the breadcrumbs, salt, and pepper and stir to combine.
The mixture should blend easily and have a smooth consistency similar to a thick batter. If you feel it’s too pasty, add an extra tablespoon or two of milk.
Add the egg mixture to the meat and combine gently with a wooden spoon or spatula. For best results, don’t overdo the mixing.
Coat a 9-1/2 x 5-1/2-inch loaf pan with nonstick spray and add the meatloaf mixture, tamping it down gently and smoothing the top.
You can bake your meatloaf in the pan if you like, but we prefer to just use the pan as a mold.
Line a shallow baking pan with heavy-duty aluminum foil and coat it with nonstick spray. Turn the meatloaf onto the pan and, using your hands, firm and smooth it into shape.
Bake for 40 minutes, then remove the meatloaf from the oven to glaze the top.
Combine the ketchup and Worcestershire in a small bowl and brush to cover both the top and sides.
Bake for an additional 15 to 20 minutes, or until the glaze is set and the meatloaf reaches an internal temperature of 155°F. Allow to rest 5 minutes before slicing.