Preheat the oven to 375°F.
Season the pork chops on both sides with salt and pepper. In a large, cast-iron skillet, heat the oil, three turns of the pan, over medium-high. When the oil ripples and smokes, add the chops and cook until browned, 2 minutes per side. Using tongs, lift the chops and brown them on the edges; transfer to a plate.
Add the shallots, garlic and rosemary to the skillet. Cook, stirring often, until the shallots soften, 1-2 minutes. Add the wine and stir until evaporated, about 1 minute more. Add the stock, capers, mustard and butter; swirling the pan to incorporate. Add the parsley then slide the pork chops back into the pan. Transfer the skillet to the oven and roast until the pork is cooked through, about 5 minutes.
Spoon some sauce from the skillet onto each plate. Top with the chops and serve with a pile of watercress and warm bread alongside.