Blanch the green beans: Bring a medium pot of salted water to a boil, add green beans and simmer until vibrant and just tender, 3-4 minutes. Drain, rinse in cold water.
Step 3
In a large bowl, add the drained beans (or drained tuna), drained artichoke hearts, drained olives, chopped celery, roasted peppers, cherry tomatoes, bell pepper, red onions, capers and fresh herbs. Add baby mozzarella balls if using.
Step 4
Whisk dressing ingredients together in a small bowl.
Step 5
Gently fold in the dressing into the salad, until combined. Taste, and add more salt or vinegar as needed-flavor will vary here based on what specific canned goods you are using.