Place barley, water and salt in large saucepan. Bring to boil.
Cover and cook on low heat for 1 hour or until tender. Drain well.
Pour Italian dressing over warm barley and toss to coat lightly. Cover and chill.
Add remaining ingredients, except garnish.
For chilled salad: Spoon barley mixture into serving bowl; chill 2 to 3 hours.
For a hot salad: Spoon mixture into a baking dish or individual ramekins. Bake at 350 ºF 15 to 20 minutes or until heated through.
Or heat in microwave over on high 2 to 3 minutes.
Garnish salad with tomato slices or wedges and lettuce leaves, if desired.