Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the ground beef, breadcrumbs, milk, chopped onion, minced garlic, eggs, Worcestershire sauce, Dijon mustard, salt, black pepper, and dried thyme. Mix until all ingredients are evenly incorporated. Be careful not to overmix.
Transfer the meat mixture into a loaf pan, shaping it into a loaf. Alternatively, shape it by hand and place it on a baking sheet lined with parchment paper.
Spread the ketchup evenly over the top of the meatloaf for added flavor and moisture.
Bake in the preheated oven for about 60 minutes, or until the internal temperature reaches 160°F (70°C).
Once cooked, remove the meatloaf from the oven and let it rest for about 10 minutes before slicing. This helps retain the juices.
Serve warm, garnished with fresh parsley if desired.