Preheat oven to 400°F.
Salt and pepper the chicken all over.
Heat the oil in a large skillet, preferably cast-iron skillet. Working in batches, if necessary, add the chicken, skin-side down, and sear until golden, about 6 minutes. Flip the chicken pieces over and cook for another 2 minutes. Transfer to a clean platter and finish the remaining chicken (if necessary). Discard excess oil in the platter but leave the bits attached to the bottom of the pan.
Return the pan to the stove over medium heat, and pour in the chicken broth. Use a wooden spoon to scrape up any bits on the bottom of the pan.
Pour the mole sauce into the pan and stir to incorporate it with the stock. Bring to a simmer.
Nestle the chicken pieces into the sauce in the pan and ladle some of the sauce over the chicken pieces.
Place in the oven for 35 minutes, covering with foil if the sauce on the chicken is getting very dark (you may not need to do this).
Remove and spoon more sauce over the top. Plate the chicken, add more sauce, and sprinkle liberally with sesame seeds.
