Roast Leg of Lamb with Potatoes and Asparagus Gremolata

Preparation

1. Lamb

   Step 1

   Whisk cumin, coriander, pepper, and 8 tsp. salt in a small bowl. Trim excess fat and any membrane from lamb; discard. Pat lamb dry with paper towels and rub with 2 Tbsp. oil. Rub spice mixture all over lamb. Place, fat cap down, on a rack set inside a roasting pan and chill, uncovered, at least 12 hours and up to 24 hours.

   Step 2

   Let lamb come to room temperature, about 2 hours.

   Step 3

   Preheat oven to 500°. Toss potatoes with remaining 2 Tbsp. oil in a large bowl; season with salt. Roast lamb 20 minutes. Turn over and roast until well browned, 5–10 minutes. Remove from oven and slide potatoes under rack in roasting pan. Reduce oven temperature to 325° and roast until potatoes are lightly browned and very tender and an instant-read thermometer inserted into the thickest part of leg registers 118° for medium-rare, 1–1½ hours. Tent pan with foil and let lamb rest 1 hour.

2. Asparagus and Assembly

   Step 4

   Cook asparagus in a large pot of boiling salted water until bright green and crisp-tender, about 1 minute. Drain and transfer to a bowl of ice water. Let cool; drain. Slice asparagus into ¼"-thick rounds; set aside.

   Step 5

   Mix scallions, garlic, pine nuts, parsley, lemon zest, lemon juice, orange zest, orange juice, honey, and red pepper flakes in a medium bowl; season with kosher salt and black pepper. Let gremolata sit at least 20 minutes, or cover and chill up to 12 hours.

   Step 6

   Ten minutes before serving, stir mint, oil, and reserved asparagus into gremolata; season with kosher salt and black pepper.

   Step 7

   Slice lamb ½" thick; season with sea salt. Toss potatoes in pan with some chives. Serve lamb topped with gremolata with potatoes alongside.