8 (1-inch-thick) rib pork chops (4 lb total)
1 teaspoon fine sea salt
1 1/4 teaspoons black pepper
2 1/2 tablespoons unsalted butter
1 lb large shallots (8), bulbs separated if necessary and each bulb halved lengthwise
1 cup hard cider
Preheat oven to 450°F.
Pat pork chops dry and sprinkle both sides with sea salt and pepper. Heat 1 1/2 tablespoons butter in a 12-inch heavy skillet over moderately high heat until foam subsides, then brown chops in 3 batches, turning once, 6 minutes per batch, and transfer with tongs to a large shallow baking pan (1 inch deep).
Add shallots and remaining tablespoon butter to skillet and cook over moderate heat, turning occasionally, until golden brown and tender, 6 to 8 minutes. Add cider and boil, stirring and scraping up brown bits, until reduced to about 3/4 cup, about 3 minutes.
Spoon shallots and sauce around chops and roast in lower third of oven until thermometer inserted horizontally into center of 1 chop (do not touch bone) registers 150°F, 7 to 9 minutes.
Let chops stand, loosely covered with foil, 5 minutes (temperature will rise to 155°F while standing). Serve chops with shallots and sauce.