Smoked Herring Mason Jar Salad

0 Whisk together the ingredients for the ranch dressing in a medium bowl, then add the herring and toss to coat.
1 Layer the spinach in the bottom of a mason jar. Toss boiled and cooled potatoes with a pinch of sea salt and layer on top of the spinach.
2 Divide the herring mixture in half and spoon over the potatoes. Top with capers and serve or screw on the lid for later serving!