Make the sauce: In a small bowl, stir the hoisin sauce, rice vinegar, and orange juice concentrate until well mixed.

Cook the chops: Pat the pork chops dry with paper towels and rub both sides with 2 tablespoons of the sesame oil, the coriander, salt, and pepper. Heat the remaining 2 tablespoons sesame oil and the olive oil in a very large saute pan over medium-high heat until hot but not smoking. (If you don't have a saute pan large enough to fit the chops without crowding, use two smaller saute pans, divide the sesame and olive oils between them, and cook two chops in each.) Cook the chops until well browned on one side, 3 to 5 minutes. Turn and cook the other side until the meat is done, 2 to 4 minutes. (If they start to burn, turn down the heat slightly.) To check for doneness, make a small cut near the bone and look inside -- the pork should have a hint of pinkness. If it's still red, cook for another minute and check again. Transfer the chops to a plate, tent with foil, and let rest for 3 to 5 minutes before serving.

Make the garnish: Put the scallions, bell pepper, and ginger in the saute pan over medium-high heat. (If you used two pans for the chops, use just one for the garnish). Cook, stirring constantly, until crisp-tender, about 2 minutes. Add the sherry; cook for another 30 seconds. Brush each chop generously with the sauce, top with the vegetables, and serve.