01 - Pat chicken breasts dry and season with salt and black pepper on both sides.
02 - Heat olive oil in a large skillet over medium-high heat. Add chicken breasts and sear until golden brown on both sides, about 4–5 minutes per side. Remove and set aside.
03 - Add chopped onion to the skillet. Cook for 2–3 minutes until softened, then stir in minced garlic and cook for 30 seconds until fragrant.
04 - Pour uncooked orzo into skillet and toast lightly, stirring continuously for 1 minute. Add chicken broth and mix well. Simmer uncovered, stirring occasionally, until orzo is just tender and most liquid is absorbed, about 8–10 minutes.
05 - Stir in heavy cream, grated parmesan cheese, and baby spinach. Continue cooking, stirring frequently, until spinach wilts and mixture is creamy, about 2–3 minutes.
06 - Return chicken breasts to skillet, nestling them into orzo, and sprinkle with crushed red pepper flakes if using. Simmer gently for 2 minutes to blend flavors, then remove from heat.
07 - Slice chicken breasts and serve atop creamy spinach orzo, garnished with additional parmesan if desired.