Heat the oven to 350°F (175°C). Use approximately 1/2 tablespoon of the measured butter to thoroughly grease a 9 x 13-inch baking pan.
Arrange half of the thinly sliced potatoes in an even layer across the bottom of the prepared baking dish.
Distribute half of the flour and half of the finely diced onion over the potatoes. Dot the surface with half of the remaining 5 1/2 tablespoons of butter, then season with salt and black pepper according to taste.
Create a second layer using the remaining potatoes, flour, onion, and butter. Season once more with salt and pepper.
Pour the 2 cups of milk evenly over the assembled potato mixture.
Cover the baking dish securely with aluminum foil. Transfer it to the preheated oven and bake for 30 minutes, allowing the potatoes to begin softening.
While the potatoes are baking, season all six pork chops on both sides with salt and black pepper. Allow them to come toward room temperature while the potatoes complete their initial baking period.
After 30 minutes, remove the baking dish from the oven. Carefully stir the potato mixture to redistribute the ingredients and encourage even cooking.
Place the seasoned pork chops in a single layer over the partially cooked potatoes.
Cover the baking dish again with foil and return it to the oven. Bake for another 30 minutes.
Remove the foil and continue baking for an additional 30 to 45 minutes.
The dish is ready when the pork chops are very tender, the potato mixture is hot and bubbling, and the potatoes around the edges are beginning to turn golden brown.