Split, stem, and seed the chilies. Toast them in a medium dry skillet over medium-high heat, flipping and flattening with a spatula, until fragrant, about 30 seconds per side. Transfer the chilies to a bowl, cover with very hot water, and set aside until soft and pliable, about 30 minutes and then drain.
Adjust the oven rack to its highest position and preheat the broiler to high. Put the tomatoes, onion, and garlic on a foil-lined baking sheet. Broil the vegetables until the skins are charred and the garlic is soft, flipping as needed, about 8 minutes for the tomatoes and onions and 3 minutes for the garlic. Cool and then squeeze the garlic out of their skins, and put in a blender along with the drained chiles, tomatoes, onion, 3/4 cup chicken broth, chocolate, almonds, oregano, cinnamon, cloves, bread and chipotle en adobo. Blend until smooth.
Heat the oil in a large Dutch oven over medium-high heat. Carefully add the mole mixture and cook, stirring, until thick and fragrant, about 5 minutes. Whisk in the remaining chicken broth. (The mole sauce can be made to this point a day ahead and refrigerated.)
Add the chicken to the sauce and simmer until the chicken is heated through, about 20 minutes. Transfer to a serving dish, scatter the sesame seeds over top and serve with rice if using.
Poached Chicken for Mole
Put the onion and chicken in a medium saucepan. Cover with the broth and 2 cups of water. Bring to a boil, then lower the heat to a simmer and cover. Cook until the chicken is just firm to the touch, about 25 minutes. Remove the pan from the heat, uncover, and cool the chicken in the liquid for about 30 minutes.
Transfer the chicken to a large dish or bowl to cool completely, then cover and refrigerate until ready to use. Strain the broth and store, covered, in the refrigerator for 3 days or freeze for later use. Remove any fat from the surface of the broth before using.
Copyright 2016 Television Food Network, G.P. All rights reserved.