1. Rinse lamb and pat dry. Place flour in a plastic bag and add about half the meat; seal bag and shake to coat pieces lightly with flour. With your hands or tongs, lift pieces out and shake off excess flour. Repeat with remaining lamb. Discard remaining flour.
2. Set a 5- to 6-quart pan over medium-high heat. Add 1 tablespoon oil and tilt to coat pan bottom. When oil is hot, add about half the meat in a single layer, pieces slightly apart. Cook, turning as needed to brown all sides, about 6 minutes total. Transfer meat to a rimmed plate and repeat to brown remaining lamb, adding 1 more tablespoon oil. Transfer second batch to plate.
3. Add onion to pan and stir until limp, about 2 minutes. Return all the lamb and any accumulated juices to pan, then stir in broth, ginger, orange peel, anise seeds, allspice, and cayenne. Bring to a boil over high heat, then cover, reduce heat to low, and simmer until meat is tender when pierced, about 1 hour.
4. Add carrots, return to a boil, reduce heat, and simmer, covered, until carrots are tender when pierced, about 20 minutes. Add beans; cover and simmer, stirring occasionallly, until hot, about 5 minutes. Stir in minced cilantro and salt to taste. Pour into a serving bowl. Garnish with cilantro sprigs.