- 1 cup extra-virgin olive oil
- 1/2 cup rosemary leaves, finely chopped
- 1 head of garlic, minced
- Finely grated zest of 1 lemon
- 2 tablespoons fresh lemon juice
- 1/2 teaspoon crushed red pepper
- Kosher salt
- One 5 1/2-pound boneless leg of lamb, butterflied
- Freshly ground black pepper
- 1 stick (4 ounces) unsalted butter
- 5 large Idaho potatoes, peeled and sliced 1/4 inch thick
- In a bowl, combine the oil, rosemary, garlic, lemon zest, lemon juice, crushed red pepper and 1 tablespoon kosher salt. Let the chimichurri stand at room temperature for at least 20 minutes.
- Preheat the oven to 500°. Season the lamb with salt and pepper and brush on both sides with 2/3 cup of the chimichurri. Set the lamb, fat side up, on a large rimmed baking sheet and roast in the upper third of the oven for about 25 minutes, or until an instant-read thermometer inserted in the thickest part of the meat registers 130° for medium rare. Transfer the lamb to a cutting board, cover with foil and let rest for 10 minutes.
- Meanwhile, divide the butter between 2 large skillets, preferably cast iron. Add one-quarter of the potatoes to each skillet and cook over low heat until browned on the bottom, about 15 minutes. Turn the slices with tongs and fry until browned on the other side, about 5 minutes longer. Transfer the potatoes to a rack set over a baking sheet, season with salt and keep warm on the back of the stove. Fry the remaining potatoes.
- Thickly slice the lamb. Arrange the potatoes on a plate, top with the lamb and spoon the chimichurri over it all.
The chimichurri is best made 1 to 2 days ahead and refrigerated. Let it return to room temperature before serving.
A Cabernet Sauvignon will echo the rosemary and match the gaminess of the lamb. Try a Chilean bottling.