Mix together the oil, garlic, mustard, rosemary leaves & vinegar.
Put the chops into a freezer bag and add the mixture.
Rub the meat through the bag, tie and marinate in the fridge for a minimum of 30 minutes, preferably for 2 hours (or even overnight).
Take the meat out of the fridge and remove from the bag, reserving the leftover marinade. Season them with salt and pepper to taste.
Heat a griddle pan, grill or BBQ and cook for 8-10 minutes until golden, turning the chops a couple of times and basting them with the marinade.
Let them rest for a couple of minutes before serving.