- Preheat oven to 400°F.
If you don’t have cooked chicken, bake the chicken breasts or chicken thighs in the oven for 25 minutes. Once cooked, place the chicken on a cutting board and use two forks to shred the chicken into bite-size pieces.
- In a 9 x 13-inch baking dish, add the diced onion, drizzle with olive oil, and stir until well coated. Transfer the baking dish to the oven for 5 minutes while you prepare the other ingredients.
- Remove the baking dish from the oven, add the orzo, minced garlic, diced sundried tomatoes, chopped spinach, kalamata olives (optional), oregano, olive oil, and salt, and stir to combine.
- Add the chicken, feta cheese, lemon juice, and lemon zest to the casserole dish, and stir again to combine with the other ingredients.
- Pour in the broth and give it a final stir until everything is well incorporated and the orzo, veggies, and chicken are mostly submerged in the liquid.
- Cover the baking dish with aluminum foil, then transfer it to the oven to bake for 15 minutes.
- Remove the baking dish from the oven, remove the foil, give everything a good stir, and then return it to the oven, uncovered, for a final 15-20 minutes until the orzo is cooked and most of the liquid has been absorbed.
- Once cooked, remove the baking dish from the oven and allow it to rest for 5 minutes before serving with a sprinkle of feta and parsley. Any leftovers can be stored in an airtight container in the fridge for up to 5 days or in the freezer for up to 3 months.