Preheat oven to 350°F. Lightly grease a 9x13-inch baking dish.
Whisk the mushroom soup, milk, and thyme with 0.25 tsp salt and 0.25 tsp pepper until smooth; set aside.
Stir flour, garlic powder, paprika, and the remaining salt and pepper in a shallow bowl.
Pat pork chops dry, then coat lightly in the seasoned flour, shaking off excess.
Heat olive oil in a large skillet over medium-high. Sear chops 2–3 minutes per side until browned; remove.
Toss sliced potatoes and onions with the melted butter to coat evenly.
Layer half the potatoes and onions in the dish. Pour on half the soup mixture.
Repeat with remaining potatoes and onions, then pour over the rest of the soup mixture.
Nestle the browned pork chops on top. Cover tightly with foil.
Bake 40 minutes. Uncover and bake 20–25 minutes more, until potatoes are tender and chops reach 145°F.
Rest 10 minutes before serving. Spoon pan gravy over the chops.