Mole Poblano Chicken

In a medium enameled cast-iron casserole, combine the chicken, bay leaves, onion, garlic, peppercorns and a generous pinch of salt. Add the broth and water and bring to a boil. Simmer over moderate heat for 20 minutes, or until the chicken is almost cooked through. Transfer the chicken to a plate and strain the broth into a heatproof bowl. Set aside 4 cups of the broth and refrigerate the remaining broth for another use. Wipe out the casserole and add the mole to it. Whisk in the 4 cups of reserved broth until smooth and bring to a boil. Season with salt. Add the chicken and any accumulated juices to the casserole and simmer over moderately low heat until cooked through, about 10 minutes. Transfer the chicken to a platter and skim any fat from the sauce. Spoon 2 cups of mole sauce over the chicken, sprinkle with the sesame seeds and pass the remaining mole sauce at the table.