Preheat oven to 425 degrees. Line 2 sheet pans with parchment paper.
Rinse & scrub potatoes. Place into a large pot and fill with water to 1 inch above potatoes. Place on burner and bring to a boil. Lower heat to a medium high and allow to cook until potatoes are fork tender about 12-15 minutes. Drain potatoes.
Place cooked potatoes onto 2 sheet pans spaced about 2 inches apart. Take a fork and smash each potato flat. Drizzle oil onto potatoes and spread evenly. Sprinkle potatoes with salt & pepper.
Place in preheated oven for 45-1 hour until crispy & golden brown.
In large mixing bowl combine yogurt, mayonnaise, lemon juice, garlic, cucumber, red onion, chives, green onions, parsley, dill, salt & pepper.
Remove potatoes from oven. Allow to cool for a few minutes. Place smashed potatoes on a cutting board & chop into bite size pieces.
Add smashed potatoes to mixing bowl with mayonnaise mixture and mix well. Refrigerate to chill.