1. Adjust oven rack to lower-middle position and heat oven to 450 degrees. Pat short ribs dry with paper towels and season with salt and pepper. Arrange ribs bone side down in single layer in large roasting pan and roast until meat begins to brown, about 45 minutes.

2. Discard any accumulated fat and juices in pan and continue to roast until meat is well browned, 15 to 20 minutes. Transfer ribs to bowl and tent loosely with aluminum foil; set aside. Stir pomegranate juice and water into pan, scraping up any browned bits; set aside.

3. Reduce oven temperature to 300 degrees. Heat oil in Dutch oven over medium heat until shimmering. Add onion, carrot, and ¼ teaspoon salt and cook until softened, about 5 minutes. Stir in ras el hanout and garlic and cook until fragrant, about 30 seconds.

4. Stir in pomegranate mixture from roasting pan and half of prunes and bring to simmer. Nestle short ribs bone side up into pot and bring to simmer. Cover, transfer pot to oven, and cook until ribs are tender and fork slips easily in and out of meat, about 2½ hours.

5. Transfer short ribs to bowl, discard any loose bones, and tent loosely with aluminum foil. Strain braising liquid through fine-mesh strainer into fat separator; transfer solids to blender. Let braising liquid settle for 5 minutes, then pour defatted liquid into blender with solids and process until smooth, about 1 minute.

6. Transfer sauce to now-empty pot and stir in vinegar and remaining prunes. Return short ribs and any accumulated juices to pot, bring to gentle simmer over medium heat, and cook, spooning sauce over ribs occasionally, until heated through, about 5 minutes. Season with salt and pepper to taste. Transfer short ribs to serving platter, spoon 1 cup sauce over top, and sprinkle with sesame seeds and cilantro. Serve, passing remaining sauce separately.