Soak barley overnight, and cook in water until soft.

Combine barley, black beans, corn, tomato, peas, chopped avocado, cilantro, salt, and pepper.

In a jar or a salad dressing shaker, mix water, lemon juice, onion, oil, and garlic. Shake well.

Pour dressing over barley mixture and mix to coat.

If serving individually, place on a bed of lettuce leaves and garnish with avocado, tomato, and lemon wedges. Serve warm or at room temperature.