Prep the beans. Drain and rinse the white beans under cold water until no foam remains. Let them drain well so the dressing doesn’t get watered down.
Chop the vegetables. Dice the cucumber and red bell pepper.
Halve the cherry tomatoes. Finely dice the red onion. Slice the olives.
Roughly chop the parsley and mint.
Whisk the dressing. In a small bowl, combine olive oil, lemon zest, lemon juice, garlic, oregano, Dijon, salt, and black pepper. Whisk until slightly creamy and emulsified.
Toss it together. In a large bowl, add beans, onion, cucumber, bell pepper, tomatoes, olives, capers, and herbs. Pour over the dressing and gently fold to coat without smashing the beans.
Adjust and rest. Taste and add more salt, pepper, or lemon if needed.
Let the salad sit for 10–15 minutes so the flavors meld. This short rest makes a big difference.
Finish and serve. Top with crumbled feta if using. Serve slightly chilled or at room temperature with crusty bread or alongside grilled chicken or fish.