Bring a large pot of salted water to a boil and cook potatoes until they are easily pierced with a fork, about 10-15 minutes. Drain the potatoes and set aside to cool. Meanwhile, put the chicken skin in a medium saute pan over medium-low heat and cook until brown and crispy to make gribenes, about 20-30 minutes. Remove with a slotted spoon reserving the fat and drain gribenes on a paper towel. Add the onions with a pinch of salt to the pan with the fat from the chicken skin and saute over medium heat until the onions soft and golden. Add the flour, sugar, salt and pepper to the onions and cook for a minute until the mixture starts to bubble. Then add white vinegar, water, Gold's Red Horseradish and Beets and Dijon mustard and bring to a boil and cook for a few minutes until thick. Stir in potato pieces and garnish with gribenes and parsley. Serve warm or room temperature.