spring lamb loin with rosemary

1 boneless lamb loin, about 2 pounds
¼ cup rosemary leaves
2 teaspoon thyme leaves
1 teaspoon whole black peppercorns
2 Tablespoons olive oil
Kosher salt
Freshly ground black pepper
6 sprigs rosemary, for garnish

One day ahead of time, fit the lamb loin in a shallow dish. Add the rosemary leaves, 1 teaspoon of the thyme, the peppercorns, and olive oil and turn the loin several times to evenly coat it with the herbs and pepper. Cover with plastic wrap and marinate in the refrigerator overnight.

Preheat the oven to 450°.

Remove the lamb from the refrigerator. Brush off and discard the marinade. Place the lamb loin on a roasting rack in a roasting pan and sprinkle all over with salt and pepper and the remaining thyme. Roast for 20 minutes until it feels slightly firm when pressed with your finger or when it registers 140° on a kitchen thermometer. The lamb will be medium-rare.

Remove the lamb from the oven and let sit for a minute. Slice the lamb loin cross-wise against the grain and divide evenly among 6 warm dinner plates. Garnish with the rosemary sprigs and serve at once.

Serves 6.