Preheat oven to 350 degrees.
Crumble ground beef into a large bowl and add panko bread crumbs, grated onion, beaten eggs, minced garlic, Worcestershire sauce, ketchup, parsley, thyme, Parmesan cheese, milk, salt and black pepper. Mix well to combine.
Prepare the meatloaf glaze by mixing the ketchup, mustard, and brown sugar in a small bowl.
Line a bread loaf pan with aluminum foil and spread a spoonful of glaze across the bottom. Add the meatloaf mixture and press into a loaf shape, then spread the remaining glaze over the top of the meatloaf.
Bake the meatloaf in the oven for 1 hour, or until it reaches an internal temperature of 160 degrees when tested with a meat thermometer.
Let the meatloaf rest for a couple of minutes, then slice and serve.