Using a gas grill, preheat on high heat and brush grill rack with olive oil. Brush both side of the veal chop with one tbsp. olive oil. Season with salt and pepper. Use tongs to prevent piercing the meat and place the chops on the rack and grill, turning once until browned, about four-six minutes per side for medium. Place on a platter and keep warm.
Over medium heat, warm three tbsp. of olive oil in a saucepan. Add the onion and sauté for 3-4 minutes, until translucent. Add the balsamic vinegar, raise the heat to medium-high and cook until the sauce has reduced by half the amount. Add the stock and cook until the liquid is reduced again by half. Whisk in butter. Add salt and pepper to taste.
Pour the sauce over the veal chops or serve on the side, garnish with parsley.