Preheat your oven to 400°F. Toss the cubed Yukon Gold potatoes with 3 tablespoons of olive oil, 1 teaspoon of salt, and 1 teaspoon of black pepper on a sheet pan, spreading them in a single layer. Roast for 30 minutes, then stir the potatoes and continue roasting for another 15 minutes until they're golden and tender. The potatoes should develop a slight crust while staying creamy inside—this creates the best texture for potato salad.

While the potatoes finish roasting, whisk together the minced garlic, red wine vinegar, Dijon mustard, red pepper flakes, remaining 1 teaspoon salt, and remaining 1/2 teaspoon black pepper in a medium bowl. Let this sit for a minute to allow the garlic to infuse into the vinegar. I like to taste the dressing at this point and adjust the seasoning—sometimes a touch more vinegar brings out the flavors beautifully.

Transfer the hot roasted potatoes from the oven to a large bowl. Pour the garlic vinaigrette over the warm potatoes and gently toss to combine—the heat of the potatoes will help them absorb the dressing flavors. Fold in the fresh chives and parsley, reserving a small pinch of each for garnish if desired. Let this sit while you prepare the sausage so the potatoes continue to absorb the flavors.

Heat 1 1/2 teaspoons of olive oil in a large skillet over medium-high heat. Add the sliced kielbasa and cook for 5-6 minutes, stirring occasionally, until the edges are lightly browned and the sausage is heated through. This brief cooking adds a slight char and brings out the sausage's smoky flavors without making it tough.

Add the warm sausage to the potato salad bowl and gently fold everything together until evenly distributed. Serve the salad warm or at room temperature. I find that this salad tastes even better after sitting for 15-20 minutes, as the flavors continue to meld together, so it's a great make-ahead dish for gatherings.