Step 1: Preheat the Oven : Preheat oven to 375°F (190°C). Line a loaf pan with parchment paper or lightly grease it with oil or butter.

Step 2: Prepare the Meatloaf Mixture : In a large mixing bowl, combine ground beef, breadcrumbs, chopped onion, garlic, egg, milk, Worcestershire sauce, salt, pepper, thyme, and parsley. Mix gently with your hands or a spoon until evenly combined. Avoid overmixing, which can make the meatloaf dense.

Step 3: Shape and Glaze : Transfer the mixture into the prepared loaf pan and shape into a loaf. In a small bowl, whisk together ketchup, brown sugar, Dijon mustard, and apple cider vinegar. Spread half of the glaze evenly over the top of the meatloaf. Reserve the rest for serving or brushing halfway through baking.

Step 4: Bake the Meatloaf : Bake uncovered in the preheated oven for 50–60 minutes. Optional: Brush remaining glaze over the meatloaf during the last 10 minutes of baking for extra shine and flavor. Check doneness with a meat thermometer — the internal temperature should reach 160°F (71°C). Let rest for 10 minutes before slicing to allow juices to redistribute.

Step 5: Prepare Mashed Potatoes : Boil potatoes in salted water for 15–20 minutes until tender. Drain and return to the pot. Add butter and milk, then mash until smooth and creamy. Season with salt and pepper to taste.

Step 6: Serve : Slice the meatloaf into even portions. Serve alongside a generous scoop of mashed potatoes. Drizzle remaining glaze or pan juices over the meatloaf for extra flavor.