Preheat and prep. Heat your oven to 425°F (220°C). Line a large baking sheet with foil or parchment for easy cleanup. Pat the chicken thighs very dry with paper towels.
Dry skin = crispy skin.
Season the chicken. In a small bowl, mix ranch seasoning, garlic powder, onion powder, smoked paprika, black pepper, and salt. Drizzle 1 tablespoon of olive oil over the chicken. Sprinkle the seasoning all over, gently lifting the skin to rub a little seasoning underneath.
Press it on so it sticks.
Start roasting the chicken. Arrange the thighs skin-side up on the baking sheet with space between them. Roast for 20 minutes to jump-start the rendering and crisping.
Toss the green beans. While the chicken starts cooking, toss the green beans with the remaining 1 tablespoon of olive oil and a pinch of salt and pepper. Keep it simple—there’s plenty of flavor coming from the pan.
Add the beans to the pan. After 20 minutes, pull the sheet out.
Scoot the chicken to one side and spread the beans on the other, tossing them lightly in the pan juices. Return to the oven.
Finish roasting. Roast another 15–20 minutes, until the chicken skin is deeply golden and the internal temperature hits 175–185°F in the thickest part. The beans should be tender-crisp with some browning.
Optional broil for extra crisp. If you want extra crackle, broil the chicken on high for 1–3 minutes, watching closely.
Rest and serve. Let the chicken rest 5 minutes.
Squeeze a little lemon over the top and sprinkle with fresh herbs if you like. Serve the beans alongside, making sure to scoop up those toasty bits.