Place the potatoes in a large bowl then drizzle over 2 tbsp olive oil, a tbsp lemon juice and season with half of the garlic, herbs, salt and pepper. Mix well then place in a large sheet pan.
Season the chicken thighs generously with salt and pepper then mix the remaining olive oil and lemon juice with the garlic and herbs. Place the seasoned chicken in between the potatoes in the sheet pan and pour over the herb mixture. Top the chicken with lemon slices (optional).
Place in the oven and allow to bake for 45-60 minutes or until the chicken is golden brown and cooked through and the potatoes are crisp and cooked. (I tossed the potatoes half-way through cooking to ensure even browning.)