Prep the chicken: Pat dry and slice into bite-size pieces or thin strips for quick cooking. Toss with salt, pepper, onion powder, paprika, and thyme.
Blanch or quick-steam the beans (optional but recommended): Microwave green beans with a splash of water for 2 minutes, or blanch in boiling water for 2–3 minutes.
Drain well. This gives you crisp-tender beans that finish perfectly in the skillet.
Sear the chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high. Add half the chicken in a single layer.
Cook 3–4 minutes per side until browned and cooked through. Transfer to a plate. Repeat with another tablespoon of oil and remaining chicken.
Build the pan base: Reduce heat to medium.
Add butter or ghee to the skillet. Stir in garlic and red pepper flakes, cooking 30–45 seconds until fragrant. Scrape up browned bits with a spatula.
Deglaze: Pour in chicken broth and simmer 1–2 minutes to reduce slightly.
Add lemon zest and half the lemon juice. Taste and adjust salt.
Add beans and finish: Toss green beans in the sauce for 2–3 minutes until coated and crisp-tender. Return chicken and any juices to the pan.
Stir to combine and warm through, 1–2 minutes.
Final touches: Squeeze in more lemon juice to taste. Sprinkle Parmesan if using. Garnish with parsley.
Serve hot.