Coat both sides of the rack of lamb with salt and pepper or desired seasonings such as Greek seasoning. Let sit at room temperature for about 30 minutes.
Submerge rosemary in a bowl of water to soak
Preheat the gas grill to medium-high heat, or 400-450° F.
Lightly grease the grill grate. Place rosemary in a small bunch over the grates to create a bed. Top with the lamb rack and close the lid. Grill for 6 to 8 minutes, or until bottoms are browned with sear marks.
Remove and discard the rosemary leaves. Rotate the rack, close the lid, and grill 5 to 7 minutes more, or until the internal temperature reaches at least 145° F for medium.
Remove the rack from the grill and let rest at least 10 minutes before serving. Slice between the bones to create lamb chops then serve.
