• Thoroughly rinse the potatoes while keeping their skins intact. In a large pot, add water to cover them, followed by a pinch of salt. Bring to a boil and cook for about 20 to 25 minutes until they can be pierced easily with a fork, avoiding overcooking.

Preparing the Sauce:

• As the potatoes cook, pour the broth into a small saucepan and simmer until it reduces by half—aim for approximately 2/3 cup. Set it aside for later use.
• Once the potatoes are cooked, drain them and allow them to cool slightly, but keep them warm. If the broth has cooled, heat it again until it's hot, then remove from heat and mix in the vinegar, mustard, and sugar until you achieve a smooth consistency. Incorporate the chopped red onion into this flavorful sauce.
• Peel one potato, slice it, and add it to the warm dressing. Gently mix it with a wooden spoon. Continue the process of peeling, slicing, and incorporating the remaining potatoes, adding each to the dressing gradually. Although it may appear watery initially, rest assured it will thicken nicely.
• Allow the salad to sit for about 30 minutes, stirring every 10 minutes to encourage the potatoes to absorb the sauce and enhance thickness.
• Drizzle in the vegetable oil and season to taste with salt and pepper. Gently stir all ingredients to combine for one last time.
• Top off the salad with freshly chopped chives for a vibrant touch and enjoy it warm or chilled—it's a perfect dish for any occasion.