Pat pork chops dry with paper towels and season both sides with salt and black pepper. Let them sit at room temperature for 5 minutes while you heat a cast iron skillet over medium-high heat for 3-5 minutes until hot.
4 bone-in pork chops, salt, black pepper
Add butter and olive oil to the hot skillet and swirl to coat. Once butter stops foaming (about 30 seconds), add pork chops with at least 1 inch space between them. Sear without moving for 3-4 minutes until golden crust forms, then flip and cook another 3-4 minutes. Remove chops to a plate when they reach 140°F internal temperature; they will rise to 145°F while resting.
4 bone-in pork chops, 2 tablespoons butter, 1 tablespoon olive oil
Lower heat to medium and add sliced onions to the skillet. Stir to coat in drippings and cook for 5-6 minutes, stirring every minute, until softened and golden edged. Add minced garlic and cook for 30 seconds until fragrant.
2 yellow onions, 2 cloves garlic
Add chicken broth or apple cider and fresh thyme sprigs. Scrape bottom of pan with wooden spoon to lift browned bits. Simmer for 2 minutes until liquid reduces by half.
0.5 cup chicken broth or apple cider, 2 sprigs fresh thyme
Add sliced apples and cook for 3-4 minutes, turning once, until apples soften slightly but still hold shape. Return pork chops to skillet and spoon apples and onions over them. Cook 1-2 minutes to warm through. Remove from heat, discard thyme sprigs, and let rest 5 minutes before serving.
4 bone-in pork chops, 2 firm apples