Prep the chicken and beans: Pat the chicken dry and season with salt, pepper, and smoked paprika if using. Trim the green beans.
Zest and juice the lemon. Chop the herbs.
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 golden and cooked through. Transfer to a plate and repeat with remaining chicken, adding a bit more oil if needed.
Blister the green beans: Reduce heat to medium. Add 1 tablespoon olive oil and the green beans.
Cook 4–5 minutes, stirring occasionally, until bright and slightly blistered. Season with a pinch of salt.
Add garlic and deglaze: Push beans to the edges. Add butter to the center; when melted, add the minced garlic.
Cook 30 seconds until fragrant. Pour in the chicken broth and scrape up any browned bits.
Bring it together: Return chicken to the skillet. Add lemon zest, 1 tablespoon lemon juice, and the chopped herbs.
Toss to coat and warm through, 1–2 minutes. Taste and adjust salt, pepper, and lemon as needed.
Finish and serve: Sprinkle red pepper flakes if you like a little heat. Serve hot with rice, quinoa, mashed potatoes, or crusty bread to catch the juices.