Heat 2 tablespoons of the oil in a large heavy skillet over medium heat. Sprinkle the pork chops with salt and pepper. Add 2 pork chops to the skillet and cook until they are browned and an instant-read thermometer inserted horizontally into the chop registers 145°F, 4 to 5 minutes per side. Transfer the pork chops to a plate and tent with foil to keep them warm. Repeat with the remaining 2 pork chops, adding more oil to the pan as needed.
Add onions to the same skillet and sauté over medium heat until crisp-tender, about 5 minutes. Add the tomatoes with their juices, herbes de Provence, and ½ teaspoon of red pepper flakes. Cover and simmer until the flavors blend and the juices thicken slightly, stirring occasionally, about 18 minutes. Season the sauce to taste with salt and more red pepper flakes if you like is spicier.
Return the pork chops and any accumulated juices from the plate to the skillet and turn the pork chops to coat with the sauce. Heat until warmed through, a minute or so. Do not overcook the chops!
Place 1 pork chop on each plate. Spoon the sauce over the pork chops. Sprinkle with the parsley (if using) and serve.