Season the chicken. Pat the chicken dry.
Toss with 1/2 teaspoon salt, black pepper, oregano, dill, and paprika. Let it sit while you prep the aromatics.
Sear the chicken. Heat olive oil in a large skillet over medium-high. Add chicken in a single layer and cook until browned on both sides and just cooked through, 5–7 minutes total.
Transfer to a plate.
Sauté the aromatics. Reduce heat to medium. In the same pan, add onion and a pinch of salt. Cook until translucent, 3–4 minutes.
Stir in garlic and red pepper flakes; cook 30 seconds until fragrant.
Deglaze. Pour in white wine (if using) and scrape up browned bits. Let it bubble for 1–2 minutes to reduce slightly.
Add orzo and liquids. Stir in the dry orzo to lightly toast for 30–60 seconds. Add chicken broth, lemon zest, and 2 tablespoons of lemon juice.
Bring to a gentle simmer.
Simmer and stir. Cook orzo uncovered, stirring every minute or so to prevent sticking, 7–9 minutes. If it looks dry before the orzo is tender, add a splash of broth or water.
Finish the skillet. Return chicken (and any juices) to the pan. Stir in spinach and olives.
Cook 1–2 minutes until spinach wilts and orzo is al dente. Add butter, if using, for extra richness.
Adjust and serve. Taste and add more salt or lemon juice if needed. Remove from heat and top with crumbled feta and parsley.
Serve hot with extra lemon wedges.