Grill lamb, covered, over medium heat for 10-20 minutes or until meat reaches desired doneness (for medium-rare, a meat thermometer should read 145°; medium, 160°; well-done, 170°). Cut into cubes.
In a large bowl, combine the lamb, artichokes, kidney beans, green beans, red pepper and onion. In a small bowl, whisk the salad dressing, vinegar and pepper; pour over salad and toss to coat. Cover and refrigerate for at least 4 hours. Serve with feta cheese if desired. Yield: 6 servings.