Pat pork chops dry with paper towels. In a small bowl, combine salt, black pepper, garlic powder, and paprika. Season both sides of the pork chops generously with the mixture.

Heat olive oil in a large skillet over medium-high heat. Sear the pork chops for 3-4 minutes per side until golden brown. They don't need to be cooked through, just nicely browned. Remove chops from skillet and set aside.

Add chopped onion to the same skillet (add a little more oil if needed). Sauté for 3-4 minutes until softened. Add sliced mushrooms and cook for another 5-7 minutes until they release their liquid and start to brown. Remove vegetables from skillet and set aside.

Preheat oven to 375°F (190°C). Lightly grease a 9x13 inch baking dish. Spread the uncooked rice evenly over the bottom of the dish. Pour 1.5 cups of chicken broth or water over the rice.

In a medium mixing bowl, whisk together the cream of mushroom soup, milk, sour cream (if using), Worcestershire sauce, and dried thyme. Season with salt and pepper to taste.

Arrange the seared pork chops on top of the rice in the baking dish. Spoon the sautéed onions and mushrooms evenly over and around the pork chops. Finally, pour the creamy mushroom sauce over everything, ensuring the chops are well coated.

Cover the baking dish tightly with aluminum foil. Bake for 45 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the rice is tender and the pork chops are cooked through (internal temperature 145°F/63°C).

Let the casserole rest for 5-10 minutes before serving to allow the sauce to set and flavors to meld. Serve hot.