Twenty minutes in advance of grilling the meat, light the charcoal or turn on the gas grill to high.
Put the garlic and olive oil in a small saucepan, turn on the heat to medium high, and cook the garlic, stirring from time to time, until it becomes colored nut brown. Add the chopped rosemary, stir once or twice, then remove from heat.
Cook the meat to the degree of doneness you prefer: for rare, which is my preference, about 3½ minutes on one side and 2 minutes on the other. When turning over the steaks, season them with salt and liberal grindings of black pepper and, at the same time, put the saucepan over a corner of the grill to reheat the oil and garlic.
When the steaks are done, transfer them to the hot platter and cut them into several thick slices, detaching the meat from the bone, should it have any. Pour the contents of the saucepan over the meat, and serve at once.