- 8 medium lamb shanks (8–10 lb. total)
- 1/4 cup kosher salt plus more for seasoning
- 10 garlic cloves, thinly sliced
- 1 1/2 teaspoons ground cardamom
- 1 cup natural unsalted pistachios, toasted, divided
- 8 small whole Seckel pears, or 4 large Bosc pears, halved
- 1/4 cup chopped flat-leaf parsley
- 1/4 cup chopped fresh mint
Place lamb in a large roasting pan. Sprinkle 1/4 cup salt over; toss to coat. Loosely cover with foil or plastic wrap and chill for 24 hours.
Preheat broiler. Divide shanks between 2 rimmed baking sheets. Broil lamb 1 sheet at a time, turning occasionally, until browned on all sides, about 15 minutes per batch.
Reduce oven to 350°. Heat oil in a large roasting pan over 2 burners set to medium-high heat. Add onion, carrots, and garlic; sautée until lightly browned, about 10 minutes. Add ground cardamom and cinnamon stick and season generously with salt; cook, stirring, for 1 minute. Stir in pomegranate juice and 3 cups water, scraping up browned bits. Add 3/4 cup pistachios and reserved lamb, arranging the meatier part of the shanks in the liquid with bones facing upward. Cover pan tightly with a double layer of foil.
Transfer roasting pan to the oven. Cook, basting and turning shanks every hour, until meat is tender and almost falling off the bone, about 3 hours.
Uncover pan. Add whole pears, pushing to submerge; let cool completely at room temperature. Cover; chill overnight. Chop remaining 1/4 cup pistachios; cover and store airtight at room temperature.
Preheat oven to 450°. Scrape fat from surface of braising liquid in pan; discard. Heat lamb mixture over 2 burners set to medium heat, occasionally shifting shanks and stirring juices, until warmed through, 10–15 minutes. Gently transfer shanks to a large rimmed baking sheet. Spoon 1 cup braising liquid over. Roast, basting occasionally, until glazed, 15–20 minutes.
Meanwhile, add rose water to roasting pan with pears and bring to a simmer. Cook until sauce thickens, 10–12 minutes.
Remove pears and reserve. Without pressing on solids, strain sauce into a bowl or measuring cup. Skim fat from surface.
Place 1 lamb shank in each bowl. Drizzle sauce over lamb. Sprinkle with herbs and reserved pistachios and serve with pears.