1Place the bacon in a large skillet and cook over medium-high heat, turning occasionally, until slices begin to brown, about 5 minutes. Drain the bacon slices on a paper towel-lined plate.
2Transfer partially cooked bacon to the bottom of a large roasting pan.
3Preheat oven to 350 degrees F (175 degrees C).
4Whisk milk and flour together in a bowl; set aside.
5Layer about one-third of the potatoes over the bacon, followed by half the onion and half the ham.
6Scatter one-fourth of the Cheddar cheese atop the ham.
7Pour one-third of the milk mixture over the cheese and season with salt and black pepper.
8Repeat the layers of potato, onion, ham, Cheddar Cheese, milk mixture, salt, and black pepper.
9Arrange the final third of potatoes in the roasting pan; pour remaining milk mixture on top.
10Scatter the remaining Cheddar cheese over the potato mixture.
11Cover roasting pan with aluminum foil.
12Bake in the preheated oven until potatoes are tender, about 2 hours.
Footnotes
Tip
Aluminum foil helps keep food moist, ensures it cooks evenly, keeps leftovers fresh, and makes clean-up easy.