Preheat the oven to 350°F (175°C). Heat vegetable oil in a large non-stick skillet over medium-high heat. Add the thawed hashbrowns, seasoning them with salt and pepper. Cook, stirring occasionally, until the hashbrowns are evenly browned. Once done, transfer them to a large bowl, reserving the skillet for later use.

In the same skillet, add one tablespoon of vegetable oil. Pat the pork chops dry and season them with salt and pepper. Brown the pork chops on both sides, ensuring they are not fully cooked, as they will continue cooking in the oven.

In the bowl with the hashbrowns, combine the cream of mushroom soup, milk, and sour cream. Mix in half of the shredded cheddar cheese and half of the dried onion pieces. Spoon the mixture into a prepared 9x13-inch baking dish. Arrange the browned pork chops on top of the potato mixture. Cover the dish with foil.

Place the dish in the oven and bake, covered, for 30 minutes. After 30 minutes, remove the foil and sprinkle the remaining onion pieces and shredded cheese on top. Continue baking, uncovered, for an additional 5 minutes, or until the cheese has melted and the dish is bubbly. Serve hot.