Bring the water to a boil and cook the potatoes for about 15-20 minutes, or until they are tender when pierced with a fork. Drain the potatoes and return them to the pot.
Add the butter, milk, sour cream, salt, and black pepper to the potatoes. Use a potato masher or a hand mixer to mash the potatoes until smooth and creamy.
If you prefer a fluffier texture, you can add a little more milk to achieve the consistency you desire.
Once the meatloaf is done, remove it from the oven and let it rest for a few minutes before slicing. This allows the juices to redistribute and ensures each slice is juicy and flavorful.
Top the mashed potatoes with the shredded cheddar cheese and place them under the broiler for about 2-3 minutes, or until the cheese is melted and bubbly. You can also sprinkle some fresh parsley on top for a pop of color and flavor.