Start by heating your oven to 400 degrees F. Prepare a 9x13 inch baking dish by greasing it lightly.

Arrange the potato slices or cubes evenly in the prepared dish.

Distribute the chopped onion and bacon over the potatoes, then add the butter cubes on top. Cover the dish with aluminum foil.

Bake in the preheated oven for 50 minutes.

After 50 minutes, take off the foil and stir the potatoes.

Switch your oven to the broiler setting and let the potatoes broil for about 5 minutes, or until they become crispy and golden brown. You may need to stir them occasionally for even browning.

Serve hot.