Heat oil in cast iron skillet over medium heat.
Season chicken thighs with salt, pepper, lemon pepper, and Italian seasoning.
Add chicken to skillet and sear 6–7 minutes per side, until cooked through.
Lower heat and add green beans, sweet peppers, and butter to the skillet.
Sauté everything together for 5–6 minutes, until veggies are tender-crisp.
Serve hot, straight from the pan.