Prepare the beans: Rinse and drain both chickpeas and kidney beans. Place them in a large mixing bowl.
Chop the veggies: Dice cucumber, onion, celery, and halve the cherry tomatoes. Add to the bowl.
Add fresh herbs: Toss in chopped parsley and cilantro (if using).
Make the dressing: In a small bowl or jar, whisk together olive oil, lemon juice, minced garlic, Dijon mustard, salt, and pepper.
Combine: Pour the dressing over the salad and toss everything together until well coated.
Chill or serve: Let it sit for 10–15 minutes for the flavors to blend, or serve immediately.
Enjoy: Serve as a main dish or as a side to grilled meat or fish.