Thoroughly wash potatoes with a vegetable brush and place in a medium size sauce pot with enough water to cover the potatoes. Allow potatoes to cook at a low boil for about 15-20 minutes, or until the potatoes are tender, and but not mushy. To test, simply pierce the potatoes with a fork and it should go through easily, but potatoes should not be mushy. Drain and allow to cool in the sink or colander.
While the potatoes are cooking, cut red pepper, green onions and celery and add to a large bowl. Cook the bacon slices until crispy, and when cooled, chop into small bites size pieces and add to the bowl (if using). Once the potatoes have cooled but still warm, cut into quarters and add to the mixing bowl.
While the potatoes are cooling, in a small bowl, whisk together, Dijon mustard, mayonnaise, apple cider vinegar, salt, pepper, olive oil, parsley and dill. Pour the dressing over vegetables and toss gently to coat thoroughly. Transfer to a serving bowl or platter.
Garnish with dill, and arugula if using. Serve warm and enjoy!