Put a dash of salt into a large saucepan filled with water and bring it to a boil. Toss in 2 pounds of 1/2 inch thick sliced fingerling potatoes and let them cook on high heat until they soften, usually taking about 10 minutes. Drain the potatoes thoroughly, making sure to shake off any remaining water.

Simultaneously, melt 1 tablespoon of unsalted butter in a large skillet. Add 3 ounces of pancetta, thickly sliced and diced into 1/4-inch squares. Keep the heat moderate and stir the pancetta regularly. After roughly 3 minutes, just as it starts to brown, add the remaining three tablespoons of butter. Continue to occasionally stir until the pancetta turns a golden color and the butter is on the verge of browning. This should take about an additional 2 minutes. Integrate a minced shallot and a sprig of rosemary, stirring it in and letting it cook for 2 minutes before removing the skillet from the heat and discarding the rosemary sprig.

In a divergent step from traditional potato salad recipes, whisk in 2 tablespoons of sherry vinegar and 1 tablespoon of grainy mustard into the pancetta blend. Season with salt and freshly ground pepper to taste. Next, add the boiled potatoes and 2 tablespoons of snipped chives into the mix, tossing everything until it's thoroughly coated. Serve this flavorful potato salad either warm or at room temperature, as per your preference.