In a large bowl, mix the chickpeas, black beans, bell pepper, tomatoes, cucumber, red onion, parsley, and mint.
In a separate small bowl, whisk together the salt, pepper, sumac, lemon juice, olive oil, and vinegar.
Pour the dressing over the salad, and toss to combine. Serve chilled or at room temperature.
Store in an airtight container in the fridge for up to 4-5 days, and toss to combine before serving.
