- 2 pounds lamb shoulder, cut into 3/4-inch chunks
 - 2 tablespoons olive oil
 - 2 medium onions, thinly sliced
 - 6 garlic cloves, thinly sliced
 - 1/4 cup red-wine vinegar
 - 7 cups reduced-sodium chicken stock or broth
 - 1 (15-to 19-ounces) can chickpeas, rinsed and drained
 - 1/4 cup apricot preserves or minced dried Turkish apricots
 - 2 teaspoons ground coriander
 - 2 teaspoons ground cumin
 - 1 teaspoon ground cinnamon
 - 1 teaspoon Maras pepper plus more for sprinkling
 - 1 teaspoon Urfa pepper plus more for sprinkling
 - 1 1/2 pounds boiling potatoes (about 4 medium)
 - 1/4 cup dried currants
 - 1/4 cup chopped oregano
 - 1 1/2 tablespoons fresh lemon juice, or to taste
 - Accompaniment: rice
 
- Pat lamb dry and season with 1 teaspoon salt and 3/4 teaspoon pepper. Heat oil in a wide 5-to 6-quart heavy pot over medium-high heat until it shimmers. Brown lamb on all sides in 3 batches until golden-brown, 4 to 5 minutes per batch, transferring to a plate with a slotted spoon.
 - Add onions to pot and cook, stirring occasionally, until golden-brown, about 8 minutes. Add garlic and cook, stirring, 1 minute. Stir in vinegar and cook, scraping up brown bits, until vinegar has evaporated, 1 to 2 minutes.
 - Return lamb with meat juices to pot. Stir in stock, chickpeas, preserves, and spices (including Maras and Urfa pepper) and simmer, uncovered, stirring occasionally, 1 hour.
 - Peel potatoes and cut into 1/2-inch pieces. Add to stew (after 1 hour) and simmer, uncovered, until potatoes and lamb are tender, about 30 minutes more. Remove from heat and stir in currants, oregano, and lemon juice. Season with salt.
 - Serve sprinkled with additional Maras and Urfa pepper.