Step 1: Preheat your oven to 350°F (175°C) and lightly grease a 9×5 inch loaf pan or line a baking sheet with parchment paper.
Step 2: In a small bowl, combine the breadcrumbs and milk. Let it sit for 5-10 minutes to form a panade.
Step 3: In a small skillet, saut) the diced onions and minced garlic in a teaspoon of olive oil over medium heat until softened and translucent, about 5 minutes. Set aside to cool slightly.
Step 4: In a large mixing bowl, combine the ground beef, the soaked breadcrumbs, beaten eggs, saut)ed onions and garlic, parsley, Worcestershire sauce, salt, and pepper.
Step 5: Gently mix the ingredients with your hands until just combined. Do not overwork the meat.
Step 6: Transfer the mixture to the prepared pan or shape into a loaf on the baking sheet.
Step 7: In a small bowl, whisk together the ketchup, brown sugar, and mustard to create the glaze. Spread half of the glaze over the top of the meatloaf.
Step 8: Bake for 45 minutes, then apply the remaining glaze and bake for an additional 15-20 minutes until the internal temperature reaches 160°F.
Step 9: Remove from the oven and let the meatloaf rest for at least 10 minutes before slicing to retain the juices.