Prepare the vegetables by rinsing and draining the Great Northern beans. Chop the cucumber and red bell pepper into bite-sized pieces. Add them with the sliced Kalamata olives and chopped pistachios to a large mixing bowl.

Chop the parsley and mint finely, and slice the green onions. Add all the herbs and onions to the bowl with the beans and vegetables. Stir gently.

Whisk together the olive oil, lemon zest and juice, minced garlic, Dijon mustard, dried oregano, honey, salt, and pepper in a separate jar or bowl.

Pour the dressing over the salad mixture and toss gently to coat all ingredients with the dressing.

Taste the salad and adjust seasoning if necessary. Let it sit for about 5 minutes before serving to allow flavors to meld.