Position a rack in the lower third of an oven and preheat to 400°F
Season the chicken thighs on both sides with salt and pepper. Tuck a few leaves of tarragon and thyme under the chicken skin. Heat the oil in a large ovenproof skillet or fry pan over medium-high heat. Add the chicken, skin side down, and cook until the fat has rendered and the skin is crisp and golden brown, about 8 minutes. Transfer, skin side up, to a plate.
Pour off the excess fat from the pan. Return the chicken, skin side up, to the pan and scatter the lemon slices on top. Transfer to the oven and roast until an instant-read thermometer inserted into the thickest part of a thigh, away from the bone, registers 170°F (77°C), 18 to 20 minutes.
Transfer the chicken and lemon slices to a platter and scatter an additional 2-3 tablespoons of fresh herbs on top. Let rest for 5 minutes before serving.