Marinate the Chicken: In a large bowl or resealable 1 gallon plastic bag, mix together the olive oil (1/4 cup), lemon zest (1 tablespoon), Dijon mustard (1 tablespoon), oregano (2 teaspoons), thyme (1 teaspoon), garlic powder (1 teaspoon), paprika (1 teaspoon), salt (1 1/2 teaspoons), and pepper (1 teaspoon). Add the chicken thighs (6) and turn to coat well. Let the chicken marinate while you prepare the vegetables, or refrigerate for 1 hour.
Start the Potatoes: Preheat the oven to 425°F (218ºC). Line a large rimmed baking sheet with heavy-duty foil for easy cleanup and lightly grease it.In a large bowl, toss the potatoes (1 pound) with 1 tablespoon olive oil, 2 teaspoons oregano (1 1/2 teaspoons), 1 teaspoon paprika, 1 teaspoon salt, and 1/2 teaspoon black pepper. Spread them in a single layer on the prepared baking sheet.Roast for 10 minutes.
Add the Chicken + Onion: Add the onion (1 medium) to the bowl and toss with the oil leftover from the potatoes.Remove the pan from the oven. Nestle the onion wedges among the potatoes. Lift the chicken from the marinade and arrange the thighs skin-side up on the pan. Return to the oven and roast for 20 minutes.
Oil Remaining Vegetables: Add the bell pepper (1 medium), tomatoes (1 pint), and garlic (6 whole cloves) to the bowl you just tossed the potatoes and onions in. Add 1 tablespoon olive oil and toss.
Add the Remaining Vegetables: Scatter the bell pepper, cherry tomatoes, garlic, and Kalamata olives (1/2 cup) around the chicken.
Continue to Roast: Continue roasting for 12–15 minutes, or until the chicken reaches 175–185°F (79-85ºC) in the thickest part of the thigh and the potatoes are tender and nicely browned and fork-tender.
Finish the Dish: Sprinkle the feta (5 ounces) evenly over the chicken and vegetables.Broil for 2–3 minutes, until the feta is just beginning to brown and soften and the chicken skin is crisp and deeply golden.
Make the Lemon-Herb Finishing Sauce: While the pan is under the broiler, whisk together the lemon juice (1/4 cup), olive oil (1 tablespoon), honey (1 tablespoon), garlic (1 clove), parsley (2 tablespoons), dill (1/2 teaspoon), salt (a pinch), and pepper until well combined. Remove the pan from the oven and immediately spoon the sauce over the chicken and vegetables.Serve immediately with warm pita, rice, or a crisp Greek salad.
Notes
Use a large rimmed sheet pan. Give the chicken and vegetables plenty of room so they roast evenly and the delicious pan juices stay safely contained.
Pat the chicken really dry. Removing excess surface moisture helps the skin brown better and gives the seasoning mixture something to cling to.
Keep the chicken skin-side up and uncovered. Don’t let the vegetables pile over the thighs—the exposed skin gets much better color in the oven.
Cut the vegetables generously. Thick onion wedges and 1½-inch pieces of bell pepper hold up better during roasting and won’t turn mushy before the chicken is done.
Spoon up those pan juices. They’re loaded with chicken drippings, lemon, garlic, and herbs. Spoon a little over each serving along with the finishing sauce.
Add the feta after roasting. This keeps its fresh, tangy flavor and gives you creamy little bites throughout the finished dish.