Season both sides of the lamb loin chops with salt and black pepper. Set aside in sealable plastic bag or container.
In a small sauce pan add the oil and garlic. Cook for 2 minutes over medium heat and add the balsamic syrup, brown sugar, rosemary and red pepper flakes. Heat to boil, reduce heat and simmer and cook for 2 minutes.
Remove from heat to cool. Pour over lamb loin chops. Turn meat over to coat on all sides, cover and refrigerate for at least an hour. The longer the better.
Preheat grill to 450°F.
Grill the chops 3 minutes on one side and 4-5 minutes on the other for medium. Baste with marinade as you grill.
