Preheat the oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment or lightly oil it.

Heat 1 tbsp neutral oil in a small skillet over medium heat. Add the chopped onion and cook for 4–5 minutes until soft and translucent. Stir in the garlic and cook for another 30 seconds until fragrant, then remove the pan from heat and let cool slightly.

In a large mixing bowl, whisk together the eggs, milk, Worcestershire sauce, Dijon mustard, 1 cup ketchup, salt, black pepper, and smoked paprika until smooth.

Add the breadcrumbs and chopped parsley to the wet mix, then fold in the cooled onion and garlic.

Add the ground beef and mix gently with your hands or a spatula until ingredients are just combined — avoid overmixing to keep the loaf tender.

Transfer the mixture into the prepared loaf pan, pat and shape into an even loaf that fills the pan.

Bake for 45 minutes.

While the loaf bakes, whisk together the glaze: Combine 1/2 cup ketchup, brown sugar, Dijon mustard, Worcestershire sauce, and apple cider vinegar until smooth.

After 45 minutes, remove the loaf and brush the glaze evenly over the top. Return to the oven for 10–15 minutes more, or until the glaze is set and the internal temperature reaches 160°F (71°C) when checked in the center.

Let the meatloaf rest for 10 minutes in the pan before turning out and slicing. Resting prevents the juices from running out and keeps slices clean.