Preheat your oven to 350°F (175°C).
Grease a 9 x 5-inch loaf pan lightly.
In a large bowl, mix the ground beef, bread crumbs, chopped onion, eggs, milk, and seasonings until combined.
Ensure the ingredients are integrated well.
Transfer the mixture into the loaf pan.
Press it evenly to ensure it shapes well.
In a small bowl, mix ketchup, brown sugar, and mustard.
Spread this glaze evenly over the top of the meatloaf.
Bake in the preheated oven for about 1 hour.
Let it rest for 10 minutes before serving to allow the juices to settle.