Preheat oven to 350°F (175°C).
Soak breadcrumbs in milk for 5 minutes in a large bowl.
Add ground beef, chopped onion, minced garlic, egg, Worcestershire sauce, salt, and ground black pepper in another bowl.
Mix gently until just combined—don’t over-mix.
Shape into a loaf and place on a lightly greased baking pan.
Mix ketchup, brown sugar, and Dijon mustard to make the meatloaf sauce.
Spread half of the sauce over the meatloaf.
Bake for 45–55 minutes, brushing with the remaining sauce halfway through.
Check that the internal temperature reaches 160°F (71°C).
Then, remove the baked meatloaf from the oven.
Let rest for 10 minutes before slicing.
Finally, serve the meatloaf with mashed potatoes, fresh salads, or roasted veggies.