This dish has direct, uncomplicated, pork-driven flavors.
Combine garlic, vinegar, Worcestershire sauce, sugar, cumin, pepper, 2 tablespoons grapeseed oil and ¤ teaspoon salt, or more, to taste, in a bowl large enough to hold chops. Add chops, turn to coat thoroughly, then transfer chops and marinade to a heavy zip-lock bag. Slip bay leaves between and around chops. Seal bag, forcing out air pockets. Refrigerate 6 to 8 hours, turning from time to time.
Light a hot fire about 6 inches from cooking grate.
Peel onions, and cut each horizontally in 3 thick slices. Thread slices on skewers. Brush with remaining oil. When coals are gray, place onions on grill. Turn after 10 minutes.
Remove chops from marinade. Place on grill with a bay leaf on each side of each chop. Brush chops and onions with some remaining marinade. Grill chops and onions, turning a few times and brushing with marinade, until chops are medium to medium-well done, about 150 degrees on an instant-read thermometer. Onions should be seared and tender.
Remove onions from skewers. Separate into rings, and tangle over the bottom of a warm platter. Place chops on onions, with a bay leaf on each chop.