In a large mixing bowl, combine the chickpeas, black beans, kidney beans, diced cucumber, sliced red onion, halved cherry tomatoes, and diced bell pepper.
In a small bowl, whisk together the olive oil, lemon juice, minced garlic, cumin, coriander, salt, and black pepper.
Pour the dressing over the bean mixture and toss to combine.
Serve immediately, or refrigerate for 15-30 minutes to allow the flavors to meld.
Notes
This hearty bean salad can be enjoyed on its own or served as a side dish with grilled meats or a whole grain like quinoa.