In a large mixing bowl, combine one can of drained and rinsed white beans, halved cherry tomatoes, and the soaked red onion.

Add in the diced cucumber and chopped fresh parsley, and mix gently until uniformly distributed.

In a separate small bowl, whisk together extra-virgin olive oil, fresh lemon juice, Dijon mustard, honey, salt, black pepper, and red pepper flakes.

Pour the dressing over the salad ingredients, and gently toss to combine.

If using, fold in capers and crumbled feta cheese, stirring gently.

Cover and marinate in the refrigerator for at least 15 minutes before serving.

Serve over a bed of fresh arugula or mixed greens.