Preheat your oven to 400°F (200°C).
In a large mixing bowl, combine olive oil, minced garlic, lemon zest, lemon juice, oregano, salt, and pepper.
Add the chicken thighs to the bowl and coat them well in the marinade. Let them sit for about 15 minutes.
In a large oven-safe skillet, heat a bit of olive oil over medium-high heat. Add the marinated chicken thighs, browning them for about 4-5 minutes on each side.
Once browned, remove the chicken from the skillet and set aside. In the same skillet, add the sliced red bell pepper and green beans, sautéing them for 3-4 minutes.
Return the chicken to the skillet on top of the vegetables, pouring any remaining marinade over the top.
Transfer the skillet to the preheated oven and roast for 25-30 minutes or until the chicken reaches an internal temperature of 165°F (75°C).
Remove the skillet from the oven and let it rest for a few minutes before serving.