Season the chicken. Pat the chicken dry and season with salt and pepper. If you have time, add a little lemon zest to the chicken now for extra flavor.

Sear in a hot skillet. Heat 1 tablespoon olive oil in a large, deep skillet over medium-high. Add half the chicken in a single layer. Cook 3–4 minutes per side until browned and just cooked through. Transfer to a plate and repeat with remaining chicken, adding oil as needed.

Soften aromatics. Reduce heat to medium. Add another drizzle of oil if the pan looks dry. Add chopped onion and a pinch of salt. Cook 3–4 minutes, stirring, until translucent and fragrant.

Toast the orzo. Stir in the dry orzo. Cook 2 minutes, stirring often, until lightly toasted. This helps the pasta stay al dente and adds flavor.

Add garlic and zest. Add minced garlic and lemon zest. Cook 30–45 seconds until fragrant. Don’t let the garlic brown.

Deglaze and simmer. Pour in the chicken broth, scraping up any browned bits. Bring to a gentle simmer. Reduce heat to medium-low.

Cook the orzo. Simmer uncovered, stirring now and then, for 8–10 minutes until the orzo is tender but still has a little bite. If it looks dry before it’s done, add a splash of hot water or more broth.

Finish with lemon and greens. Stir in the lemon juice, butter (if using), and spinach. Cook 1–2 minutes until the greens wilt and the sauce looks silky.

Return the chicken. Add the chicken and any juices back to the pan. Stir in Parmesan and parsley. Taste and adjust seasoning with more salt, pepper, or lemon juice.

Serve warm. Spoon into bowls. Top with extra herbs, a pinch of red pepper flakes, and lemon wedges on the side. The orzo will continue to thicken as it sits.