Sear the chicken.Season chicken with, garlic powder, salt and pepper. Heat 2 tablespoon olive oil in a skillet or Dutch oven, then sear chicken on both sides until golden (about 3–4 minutes per side). Remove and set aside.
Sauté aromatics.Add the butter, onion, and garlic to the same pan. Cook until softened and fragrant, about 3 minutes.
Toast the rice.Stir in the arborio rice, coating it in the butter and aromatics. Toast for 1–2 minutes.
Deglaze.Add the white wine and stir, scraping up the browned bits.
Simmer.Pour in warm broth. simmer for 10- 12 minutes or until the rice is almost cooked Cut the chicken into medium dice or strips Return the chicken (and any juices) to the pan. Cover and cook on low for an additional 5-7 minutes, stirring occasionally, until rice is tender and chicken is cooked through.
Finish.Stir in spinach (if using). Remove from heat, mix in Parmigiano Reggiano and parsley, and adjust seasoning with salt, pepper, and red pepper flakes.