Season the Chicken: Pat chicken dry and season evenly with salt, pepper, garlic powder, and oregano.
Sear the Chicken: Heat olive oil in a large skillet over medium-high heat. Add chicken and cook 4–5 minutes per side until golden and cooked through. Remove and set aside.
Cook the Aromatics: In the same pan, add diced onion and cook for 2–3 minutes until softened. Add garlic and cook for 30 seconds.
Toast the Orzo: Stir in dry orzo and cook for 1 minute to lightly toast.
Simmer the Orzo: Pour in chicken broth, bring to a gentle simmer, and cook for 8–10 minutes, stirring occasionally, until orzo is tender and creamy.
Make it Creamy: Lower heat and stir in Greek yogurt, lemon zest, lemon juice, and Parmesan until smooth.
Add Spinach: Fold in spinach and let it wilt into the orzo.
Finish the Dish: Return chicken to the pan and simmer for 2–3 minutes to warm through and absorb flavor.