Prep the beans: Drain and rinse all three cans of beans under cold water until the water runs clear. This removes extra sodium and helps the dressing cling better.

Chop the veggies: Dice the red onion, bell pepper, and cucumber into small, even pieces so they distribute throughout the salad. If the onion is sharp, soak it in cold water for 5 minutes, then drain.

Mix the vinaigrette: In a small bowl or jar, whisk the olive oil, lemon juice, red wine vinegar, Dijon, garlic, honey, salt, pepper, and red pepper flakes. Taste and adjust acid or salt as needed.

Toss it together: In a large bowl, combine the beans, chopped veggies, herbs, and briny add-ins. Pour in about two-thirds of the vinaigrette and toss gently to avoid smashing the beans.

Adjust and season: Add more dressing as needed to lightly coat everything. Fold in the nuts or seeds and feta, if using. Taste for salt, lemon, and heat.

Let it rest: For the best flavor, cover and chill for at least 30 minutes. The beans will absorb the dressing and the salad will taste more cohesive.

Serve: Give it a quick toss, add a squeeze of lemon if it needs a lift, and finish with a drizzle of olive oil and a pinch of flaky salt.