Step 1

Let pork chops stand at room temperature for 10 minutes. Pat dry with paper towels and sprinkle evenly with salt and 1/2 teaspoon pepper. Heat 2 tablespoons oil in a large cast-iron skillet over medium-high heat; add the pork chops and cook, undisturbed, until golden brown on 1 side, 4 to 5 minutes. Flip and cook for 1 minute more. Transfer the pork chops to a plate (they will not be cooked through); do not wipe the pan clean.

Step 2

Add mushrooms to the pan; cook over medium-high heat, stirring occasionally, until golden brown, about 4 minutes. Add shallot, garlic and the remaining 1 tablespoon oil; cook, stirring occasionally, until the shallot is softened, about 3 minutes. Add sherry; cook, stirring constantly and scraping up browned bits from the bottom of the pan, until the liquid is almost completely reduced, about 1 minute. Add soup and water; cook, stirring, until the mixture comes to a simmer. Stir in Worcestershire, mustard and the remaining 1/4 teaspoon pepper.

Step 3

Nestle the pork chops, browned-side up, into the mixture in the pan; cook over medium-high heat until an instant-read thermometer inserted in the thickest portion registers 145°F, about 8 minutes. Transfer the pork chops to 4 plates or a large platter; spoon the mushroom sauce over the chops. Sprinkle with chives.