Wheat Berry & Barley Salad

1 cup wheat berries 1 cup pearl barley 1 small red onion, finely diced 3 -4 cloves roasted garlic, mashed 1/4 cup balsamic vinegar 1/4 cup extra-virgin olive oil 6 green onions, thinly sliced 1 (10 ounce) bag frozen corn, thawed 1/2 lb smoked mozzarella cheese, diced (or fresh mozzarella or feta) 1 pint cherry tomatoes, halved salt & freshly ground black pepper Bring a pot of salted water to a boil. Add wheat berries. Return to a boil, then reduce heat to a simmer and cook for 30 minutes. Add barley and continue to simmer for another 30-40 minutes, or until grains are tender, but still firm. Meanwhile, combine red onion, garlic, vinegar and oil in a large bowl. Drain grains and add to onion mixture. Toss well and cool. Add green onions, corn, mozzarella, tomatoes and salt and pepper. Toss well. Salad may be made 1 day ahead and chilled, covered. Bring to room temperature before serving.