Drain and rinse the chickpeas well under cold water, then let them drain.
Dice the tomato into small cubes.
Peel the cucumber if desired, then cut it into small cubes.
Finely chop the red onion. If you prefer, soak it in cold water for a few minutes to mellow the flavor.
Dice the green bell pepper into small cubes.
Roughly chop the parsley.
In a large bowl, combine the chickpeas, tomato, cucumber, red onion, green bell pepper, and parsley.
In a small bowl, whisk together the olive oil and lemon juice. Season with salt and freshly ground black pepper to taste.
Pour the dressing over the salad and gently toss to coat.
Cover the bowl and refrigerate for at least 15 minutes before serving.