Heat olive oil in a large pot over medium heat.
Season and cook chicken until golden and fully cooked. Remove and set aside.
In the same pot, sauté onion until soft, then add garlic and cook 1 minute.
Stir in orzo and toast lightly for 1–2 minutes.
Add chicken broth, lemon juice, and lemon zest. Bring to a simmer.
Cook until orzo is tender and liquid is mostly absorbed, stirring occasionally.
Return chicken to the pot. Add cherry tomatoes and spinach.
Stir until spinach wilts and everything is well combined.
Turn off heat and mix in feta cheese and olives.
Garnish with parsley and serve warm.