Adjust oven rack to middle position and heat oven to 400 degrees. Spray rimmed baking sheet with vegetable oil spray.
Toss potatoes, 2 tablespoons oil, and 1 teaspoon salt in bowl until potatoes are well coated. Arrange potatoes in single layer on prepared sheet, cut side down. Roast until bottoms of potatoes are golden brown, 35 to 40 minutes.
Meanwhile, combine pepperoncini, lemon zest and juice, garlic, oregano, remaining 3 tablespoons oil and remaining 1/4 teaspoon salt in large bowl.
Transfer potatoes to pepperoncini mixture in bowl. Add half of parsley and toss to combine. Transfer potatoes to serving dish. Sprinkle with remaining parsley. Serve warm and pass with Feta if desired.
Bake, Assemble
2024