Preheat the Oven: Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan or line it with parchment paper.

Prepare the Meatloaf Mixture: In a large mixing bowl, combine the ground beef, breadcrumbs, onion, garlic, egg, milk, Worcestershire sauce, parsley, thyme, salt, and pepper. Mix gently with your hands or a spoon until well combined, but avoid over-mixing to prevent a tough loaf.

Shape the Meatloaf: Place the meat mixture into the prepared loaf pan and gently press it down to shape it evenly.

Make the Glaze: In a small bowl, mix together the ketchup, brown sugar, and vinegar or mustard (if using). Spread this glaze evenly over the top of the meatloaf.

Bake: Bake the meatloaf in the preheated oven for 55-65 minutes, or until the internal temperature reaches 160°F (71°C). Use a meat thermometer to ensure it’s fully cooked.

Rest and Serve: Once done, remove the meatloaf from the oven and let it rest for about 10 minutes before slicing. This helps retain moisture and makes it easier to cut.

Serve: Slice and serve with mashed potatoes, roasted vegetables, or any side of your choice.