Heat a large skillet with a lid over medium heat. Add ¼ cup chicken broth and green beans. Cover and steam for 5 minutes. Remove lid and cook 2–3 more minutes until liquid evaporates. Transfer green beans to a plate.
In a small bowl, combine 1 teaspoon salt, pepper, garlic powder, and smoked paprika.
Pat chicken thighs dry and season both sides generously with the spice mixture.
Add oil to the same skillet over medium-high heat. When hot, add chicken thighs in a single layer. Cook 5–7 minutes per side until golden and fully cooked. Transfer to the plate with green beans.
Reduce heat to medium. Deglaze pan with remaining ¼ cup chicken broth, scraping up browned bits.
Add minced garlic, lemon juice, remaining ¼ teaspoon salt, and red pepper flakes. Simmer on low until sauce reduces by half.
Stir in butter and cook 1–2 minutes until melted and slightly thickened.
Return chicken and green beans to the skillet. Spoon sauce over and simmer 2–3 minutes until heated through.
Serve your Lemon Garlic Butter Chicken and Green Beans Skillet with fresh parsley, dill, and lemon slices if desired.