Step 1

Preheat the oven to 375 degrees F.

Step 2

In a large bowl, gently combine the beef, the onion, the breadcrumbs, the milk, the egg, the salt, and the pepper together.

Step 3

Press the meat mixture into a 9x9-inch baking dish.

Step 4

Bake the meat mixture, uncovered, for 15 minutes. Drain the excess fat.

Step 5

While the meat is cooking, in a large pot, add the potatoes with just enough water to cover them, and bring the potatoes to a boil over high heat.

Step 6

Cook the potatoes until they are tender, about 15 minutes.

Step 7

Drain the water from the potatoes.

Step 8

Add the butter, the milk, the salt, and the pepper to the potatoes and mash to combine.

Step 9

Spread the potato mixture over the meat and top with the bacon and the cheese.

Step 10

Bake the meatloaf until the bacon is sizzling, the cheese is bubbling, and the potatoes are slightly crispy, about 15 minutes.

Step 11

Serve.