Slit the pork chops from the edge of the eye to the bone with a sharp knife, to make pockets for the stuffing. Combine breadcrumbs, butter, garlic, onion, rosemary, marjoram and salt. Fill the pockets with stuffing and use a skewer if necessary to close the pockets securely. Grill the pork chops over medium-high heat for 8-10 min. per side, turning several times, until the fat is crisp and the meat nicely browned.