In a 5-quart saucepan with a tight-fitting lid, heat oil over high heat. Swirl to coat bottom of pan. Season lamb with salt and pepper; cook until browned, 3 to 5 minutes. Transfer to a plate.
Reduce heat to medium. Add onion and garlic; cook, stirring occasionally, until softened, 2 to 4 minutes. Add paprika, apricots, prunes, tomatoes, and 3 cups water. Bring to a boil; reduce heat. Simmer, partially covered, until tomatoes begin to break apart and sauce is thickened, 25 to 30 minutes.
Return lamb and any accumulated juices to pan; cook until heated through, about 1 minute. Stir in cilantro and lime juice. Serve lamb with couscous, if desired; garnish with more cilantro.