Wash and dice the potatoes into one centimeter cubes. Add the potatoes and salt to a large pot of cold water and place over high heat covered. Once boiling, remove the lid and cook for eight to ten minutes, or until the potatoes are fork tender but still slightly firm.
Drain the potatoes and transfer to a large mixing bowl. Sprinkle two tablespoons of apple cider vinegar over the hot potatoes and then set them aside to cool.
In a separate bowl whisk together the 1/4 cup apple cider vinegar, grainy mustard, honey and canola oil.
Once the potatoes are cool, gently mix in the dressing and chopped chives. Refrigerate until ready to serve.