Place the chicken, onion, garlic and salt in a large pot, cover in water and boil until the chicken is cooked, about 30 minutes.
Remove the chicken, set it aside to cool and strain the water that it was cooked in.
Heat the oil in a pan over medium high heat. Fry the chilies until they start to change colour, about 20-30 seconds and let drain on paper towels.Bring the chilies and 2 cups of the reserved chicken water to a boil in a large sauce pan, reduce the heat and simmer until very soft, about 30-40 minutes.Puree the chilies in a food processor with some of the water that they were cooked in.Strain the chili puree though a fine mesh sieve. (Note: You will need to push the the mixture to get it through the sieve.)
Heat the oil that the chilies were fried in over medium.
Add the chili puree and simmer until it thickens, about 15 minutes.Toast the almonds, pecans, peanuts, pepitas and sesame seeds in batches.Puree the almonds, pecans, peanuts, pepitas, sesame seeds in a food processor along with 1/4 cup of the reserved chicken water.
Add the mixture to the chili puree and continue to simmer over low.Broil the tomatoes, tomatillos, onion and garlic until charred on all sides and set aside.
Heat the oil in a pan over medium high heat.
Add the plantain and fry until golden brown, about 2-3 minutes per side and set aside on papaer towels to drain.Puree the tomatoes, tomatillos, onion and garlic in a food processor.
Add the tomato puree to the pan that the plantain was cooked in and simmer until it thickens, about 25 minutes.
Add the plantain and raisins to the tomato sauce and simmer until soft, about 10 minutes.Puree the mixture and add it to the chili sauce and continue to simmer on low.Toast the cloves, star anise, cinnamon, allspice and peppercorns and grind in a coffee grinder.
Add the ground spices along with the oregano and salt to the mole and continue to simmer on low.
Heat the oil in a pan over medium-high heat.
Add tortilla bits, fry and set aside to drain on paper towels.Pulse the bread and tortillas in a food processor until they form bread crumbs.
Mix the bread crumbs, chocolate and brown sugar into the mole sauce and simmer over low heat for 30 minutes adding more chicken water as neccessary.