Rinse & drain chickpeas: Tip chickpeas into a colander, rinse well, and drain thoroughly (shake off excess water).
Chop produce & herbs: Dice cucumber and onion; halve tomatoes; finely chop parsley, dill, and mint. Pat veg dry if very wet for best texture.
Whisk or shake: In a small bowl or jar, combine olive oil, lemon juice, red wine vinegar, Dijon, honey, garlic, salt, pepper, and red pepper flakes (if using). Whisk or shake until emulsified.
Toss: In a large bowl, add chickpeas, cucumber, tomatoes, and onion. Pour over dressing and toss gently to coat.
Fold in herbs: Add parsley, dill, and mint. Toss again. Taste and adjust salt, acid (lemon), and heat (red pepper).
Finish: Sprinkle in feta if using. Zest a little lemon over the top and add dill fronds or flaky salt to serve.