It's an uncommon idea--grilling potatoes. We smash them, mash them, roast them, broil them, twice bake them, boil them, fry them .. pretty much everything under the sun to them. But grill them? Seems a little unheard of. Until now. This is very much a visual dish, so it is imperative that you use the Yukon Gold potatoes. If cooked entirely on a grill, this dish is best done on a gas grill, where you can control the temperature with more ease than charcoal.
Prep Peel the potatoes, and slice them into large wedges. You want at least one surface of the wedge to be long and flat, so you can get those nice grill marks. Make a rough chop of the garlic.
Put the wedges in a bowl along with the lemon juice, lemon zest, rosemary stalks, salt, and garlic. Mix together and cover tightly. Marinate in the fridge for about an hour.
Fire up on side of your propane grill to a high temperature. When the grates are hot, remove the bowl from the fridge and pick out the potato wedges. Reserve some of the garlic and rosemary. Lay the wedges gently down over the heat and grill until the edges have nice grill marks or have started to turn brown and get crusty.
Remove the wedges from the heat and into a roasting pan. add a little bit of the liquid, a few pieces of garlic, and a sprig or two of rosemary. Cover the pan lightly with foil and stick the whole pan in the grill over indirect heat. Roast for 13-15 minutes at 400 degrees.