Preheat your oven to 350°F (175°C). Line a rimmed baking sheet with foil and place a lightly greased wire rack on top. This helps the loaf cook evenly and avoids soggy bottoms. If you prefer, you can use a loaf pan, but leave some space at the sides for juices to escape.

Warm a small skillet over medium heat. Add olive oil or butter and sauté the diced onion with a pinch of salt for 4–5 minutes until soft and translucent. Stir in the garlic and cook 30 seconds more. Let cool slightly so it doesn’t scramble the egg in the mixture.

In a large bowl, combine the breadcrumbs and milk. Let stand 2–3 minutes until the milk is absorbed. This mixture, called a panade, keeps the meatloaf tender.

Add the egg, ketchup, Worcestershire, Dijon, salt, pepper, smoked paprika, and parsley to the soaked breadcrumbs. Stir until smooth and well mixed.

Add the ground beef and ground pork to the bowl. Using clean hands, gently mix just until combined. Do not overmix or the meatloaf can turn dense.

Transfer the mixture to your prepared rack or pan and shape into a loaf about 8 inches long and 4 inches wide. Smooth the top so the glaze spreads evenly.

Whisk together the glaze ingredients in a small bowl: ketchup, brown sugar, vinegar, Worcestershire, and pepper. Brush about half the glaze over the loaf.

Bake for 35 minutes. Remove from the oven, brush with the remaining glaze, and return to the oven for another 15–20 minutes, until the center reaches 160°F (71°C) on an instant-read thermometer.

Rest the meatloaf for 10 minutes before slicing. This helps the juices redistribute and keeps the slices intact.

Slice with a sharp knife and serve warm. Spoon any pan juices over the slices for extra flavor.