In a large mixing bowl, whisk together the fresh orange juice (⅓ cup), orange zest (1 tablespoon), finely chopped garlic, chopped fresh thyme, smoked paprika, ground coriander, and 3 tablespoons of the extra-virgin olive oil. Add the chicken thighs, turning each piece to ensure it's well-coated. Cover the bowl and allow the chicken to marinate in the refrigerator for at least 45 minutes, or up to 4 hours for a more intense flavor.

Preheat your oven to 400°F (205°C). On a baking sheet, toss the red onion wedges and cherry tomatoes with 1 tablespoon of the extra-virgin olive oil and a light sprinkle of coarse sea salt and black pepper. Arrange them in a single layer and roast for 15-20 minutes. You're looking for the onions to be tender with lightly charred edges and the tomatoes to be softened and just beginning to split. Once done, remove from the oven and set aside. Reduce the oven temperature to 375°F (190°C) for a subsequent step.

Take the chicken from the marinade, allowing any excess to drip back into the bowl; you can reserve a tablespoon or two of this leftover marinade for later. Gently pat the chicken pieces dry with paper towels. Season all sides of the chicken generously with the ¾ teaspoon coarse sea salt and ¾ teaspoon freshly cracked black pepper. Heat the final tablespoon of extra-virgin olive oil in your 12-inch oven-safe deep sauté pan or Dutch oven over medium-high heat until it shimmers. Carefully introduce the chicken pieces, presentation side facing downwards, into the heated pan. Allow them to cook, without moving, for about 8-10 minutes, until a rich, golden-brown crust develops. Flip the chicken pieces and continue cooking for another 5-6 minutes to brown the second side. The chicken will not be fully cooked at this point. Transfer the seared chicken to a clean plate. Avoid wiping the pan clean.

Introduce the uncooked orzo directly into the same pan. Stir it frequently over medium heat for 2-3 minutes, allowing the grains to toast lightly and become fragrant. If you reserved any marinade, add it now along with the roughly chopped Castelvetrano olives. Stir for one more minute to meld the flavors. Pour in approximately ½ cup of the low-sodium chicken stock to deglaze the pan, using a wooden spoon to gently scrape up any flavorful browned bits from the pan's bottom.

Pour the remaining 2 cups of low-sodium chicken stock into the pan with the toasted orzo. Stir to combine and bring the liquid to a gentle bubble. Incorporate the previously roasted onions and tomatoes into the orzo mixture. Position the seared chicken pieces on top of the orzo and vegetables. Cover the pan tightly with its lid or heavy-duty aluminum foil. Carefully transfer the entire pan into the preheated 375°F (190°C) oven. Bake for 20-25 minutes. The dish is ready when the orzo is tender, most of the liquid has been absorbed, and an instant-read thermometer inserted into the thickest part of a chicken thigh (steering clear of the bone) confirms a temperature of 170°F (77°C).

Cautiously retrieve the pan from the oven. Adjust the oven setting to broil (high heat) and ensure an oven rack is in the upper-middle position (about 5-6 inches from the broiler element). Uncover the pan and situate it under the broiler. Broil for 3-5 minutes. The aim is for the chicken exterior to become exceptionally browned and delightfully crisp. Maintain vigilant observation during this stage to prevent any charring beyond preference.

Once crisped, remove the pan from the broiler. Allow the dish to stand, uncovered, for 7-10 minutes before dishing it out. This resting period permits the chicken juices to redistribute, ensuring succulence, and allows the orzo to settle. Adorn generously with fresh dill fronds. Present immediately, accompanied by orange wedges on the side for a final zesty squeeze over each portion.