In a small bowl, whisk together the apple cider vinegar, Dijon mustard, minced garlic, dried oregano, salt, and freshly ground black pepper. Slowly drizzle in the extra virgin olive oil while whisking constantly to emulsify the dressing, then finish with the fresh lemon juice. Set aside at room temperature so the flavors can meld while the potatoes cook. I like to make the vinaigrette first because it allows the garlic and herbs to bloom in the acidic environment, creating a more cohesive flavor base.

Cut the Yukon Gold potatoes into evenly-sized pieces (about 2-3 inches) to ensure even cooking. Bring a large pot of water to a boil and add 1 1/2 tablespoons of salt, then add the potatoes. Boil for 15-20 minutes until the potatoes are just tender when pierced with a fork but still hold their shape. Drain thoroughly and let cool for 5-10 minutes until they're just warm enough to handle comfortably, then peel and cut into 1-inch cubes. The potatoes should still be warm when you combine them with the dressing so they absorb the vinaigrette more effectively.

While the potatoes are cooling, finely dice the red onions and slice the green onions, keeping the white and light green parts separate from the dark green tops. Chop the fresh parsley and fresh dill, and halve the Kalamata olives. Have the capers drained and ready. Doing this prep work in advance ensures you can quickly assemble the salad while the potatoes are still warm and receptive to absorbing the dressing.

Transfer the warm cubed potatoes to a large bowl, then add the diced red onions, white and light green parts of the green onions, chopped parsley, chopped dill, halved olives, and capers. Pour the vinaigrette from Step 1 over the potato mixture and gently toss until everything is evenly coated. Let the salad sit for 5-10 minutes to allow the warm potatoes to fully absorb the dressing, then taste and adjust seasonings if needed.

Top the potato salad with the reserved dark green parts of the sliced green onions for a fresh finish and visual appeal. Serve the salad warm or at room temperature. I recommend serving it within 2-3 hours of making it while the textures are at their best, though it keeps well in the refrigerator for a day if needed.