Preheat the oven to 350°F (175°C) to ensure even cooking of the meatloaf.
In a large bowl, combine the ground beef, breadcrumbs, chopped onion, minced garlic, shredded cheddar cheese, milk, egg, Worcestershire sauce, Italian herbs, salt, and pepper. Mix well, being careful not to overwork the meat.
Transfer the meat mixture to a greased loaf pan, pressing it evenly into the pan. Bake in the preheated oven for 60-70 minutes or until cooked through and the internal temperature reaches 160°F (70°C).
While the meatloaf is baking, place the cubed potatoes in a pot of salted water. Bring to a boil and cook for 15-20 minutes or until tender. Drain well.
Return the drained potatoes to the pot. Add the sour cream and butter, and mash until creamy. Season with salt and pepper to taste.
After baking, let the meatloaf rest for 10 minutes before slicing. Serve the meatloaf slices with a generous portion of mashed potatoes. Optionally, garnish with chopped chives for a fresh touch.
Notes
For an extra touch, drizzle melted cheese over the meatloaf before serving, and add a pinch of grated nutmeg to the mashed potatoes.