01 - Set oven temperature to 400°F (200°C) and allow to fully preheat before continuing.
02 - Combine halved potatoes and sliced red onion in a large mixing bowl. Drizzle with olive oil, add minced garlic, oregano, thyme, sea salt, and black pepper. Toss by hand or with a spatula to ensure complete coating.
03 - Spread the seasoned potatoes and onions evenly in a single layer on a baking dish or rimmed baking tray.
04 - Place in the oven and roast for 25–30 minutes, stirring halfway through cooking time, until the potatoes are fork-tender and lightly golden.
05 - Remove the tray from the oven and evenly sprinkle crumbled feta over the potatoes. Return to the oven and continue baking for 10–12 minutes until the cheese is softened and beginning to brown.
06 - For enhanced browning, place under the broiler for 1–2 minutes, watching closely to avoid burning.
07 - Remove from oven, garnish with lemon zest and fresh parsley if desired, and serve immediately while hot.