In a large mixing bowl, combine ground chicken, feta, breadcrumbs, egg, half of the garlic, oregano, half of the parsley, half of the lemon zest, salt, and pepper.
Form the mixture into 16 uniform meatballs.
Heat olive oil in a large skillet over medium-high heat. Sear meatballs for 8-10 minutes, turning occasionally until cooked through to an internal temperature of 165°F (74°C). Remove from pan and set aside.
Add the remaining garlic and dry orzo to the skillet. Toast for 1-2 minutes until the orzo is slightly fragrant.
Pour in the chicken broth and bring to a simmer. Cover and cook for 8-10 minutes until the liquid is absorbed and orzo is tender.
Stir in the baby spinach, lemon juice, remaining lemon zest, and remaining parsley until the spinach is wilted.
Return the meatballs to the skillet and toss gently to combine and reheat.
Serve immediately while warm.