Sprinkle pork chops with salt and pepper. Coat a large nonstick skillet with cooking spray and place over medium heat. Add the pork chops and cook until browned on both sides and cooked through, 2 to 3 minutes per side. Transfer to 2 serving plates; tent with foil to keep warm.

Swirl oil into the pan, add shallot and cook, stirring, until soft, about 30 seconds. Add mushrooms and cook, stirring occasionally, until they soften and begin to brown, about 2 minutes. Add vermouth and cook for 15 seconds. Stir in mustard, thyme and any juices that have accumulated from the pork; cook until the sauce is thickened and slightly reduced, 1 to 2 minutes more. Spoon the sauce over the pork chops and serve immediately.

Tip: To pound the chops flat, place them between two sheets of plastic wrap on a stable surface. Pound steadily with the smooth side of a meat mallet or the bottom of a heavy saucepan until 1/4 inch thick.