Preheat an oven. Bring a large pot of water to a rapid boil. Submerge the string beans into the boiling water. Cook, then transfer to a prepared ice bath. Cool.
Return the large pot of water to a rapid boil. Add Kosher salt and baking soda. Carefully add the potatoes, then cook. Drain, then return the potatoes to the warm pot.
Drizzle olive oil on a rimmed baking sheet, then pour the potatoes on top. Use your hands or a spatula to spread into a single even layer. Cook, flipping the potatoes once halfway through cook time.
Make the dressing. Combine extra virgin olive oil, lemon juice, chopped oregano, thinly sliced chives, garlic, honey, Kosher salt, and black pepper in a mason jar. Shake.
When ready, place blanched green beans on a large platter. Top with crispy potatoes, sliced red onion, Kalamata olives, and feta cheese.
Bring the heat back up to medium to medium-high, then cook to thicken. Taste and adjust seasoning.