Preheat the oven to 425°F (220°C). Line a large baking sheet with parchment paper for easy cleanup.
In a large bowl, combine the lemon zest, lemon juice, olive oil, minced garlic, oregano, thyme, salt, and black pepper. Whisk until well combined.
Add the chicken thighs to the bowl and coat them thoroughly with the marinade. Let them marinate for at least 15 minutes (or up to 2 hours in the refrigerator for more flavor).
In another bowl, toss the halved baby potatoes with a drizzle of olive oil, salt, and pepper until evenly coated.
Arrange the marinated chicken thighs on one side of the prepared baking sheet and the seasoned potatoes on the other side.
Roast in the preheated oven for 25 minutes. After 25 minutes, add the green beans to the baking sheet and toss everything gently to combine.
Return to the oven and roast for an additional 15-20 minutes, or until the chicken reaches an internal temperature of 165°F and the potatoes are tender.
Remove from the oven and let rest for 5 minutes. Garnish with fresh parsley before serving.