Wash the waxy potatoes thoroughly, then cut them into evenly sized pieces. Place in a large pot, cover with cold salted water, and bring to a boil. Cook for 15-20 minutes until fork-tender. Drain and cool.

In a medium bowl, whisk together olive oil, lemon juice, red wine vinegar, Dijon mustard, and minced garlic. Season with salt and pepper to taste.

In a large mixing bowl, combine cooled potato pieces, Kalamata olives, feta cheese, parsley, and dill. Pour the dressing over and toss gently to combine.

Let the salad sit for about 30 minutes at room temperature or refrigerate for up to 24 hours to allow flavors to meld.