In a 2 gallon stockpot, heat 5 quarts water and onions, celery, and carrots to a boil. Add chicken pieces and poach, covered, over low heat for about 35 to 45 minutes, until cooked through and juices run clear when pierced with a fork. Remove the meat from the stock. Strain and reserve the stock.
Heat 2 quarts of water in a kettle. On a 10-inch dry comal, griddle, or in a cast-iron frying pan, toast the chiles over medium heat until blackened, but not burnt, about 10 minutes. Place the chiles in a large bowl, cover with hot water, and soak for 1/2 hour. Remove the chiles from the soaking water with tongs, placing small batches in a blender with 1/4 cup of the chile soaking water to blend smooth. Put the chile puree through a strainer to remove the skins.
In the same dry comal, griddle, or frying pan, grill the onion and garlic over medium heat for 10 minutes. Set aside. Toast the almonds, peanuts, cinnamon stick, peppercorns, and cloves in a dry comal, griddle or cast-iron frying pan for about 5 minutes. Remove them from the pan.
Over the same heat, toast the chile seeds, taking care to blacken but not burn them, about 20 minutes. Try to do this outside or in a well-ventilated place because the seeds will give off very strong fumes. When the seeds are completely black, light them with a match and let them burn themselves out. Remove from the heat and place in a bowl. Soak the blackened seeds in 1 cup of cold water for 10 minutes. Drain the seeds and grind them in a blender for about 2 minutes. Add the blended chile seeds to the blended chile mixture.
Heat 3 tablespoons of oil in an 8-inch cast-iron frying pan over medium heat until smoking. Add the raisins and fry them until they are plump, approximately 1 minute. Remove from the pan. Fry the bread slice in the same oil until browned, about 5 minutes, over medium heat. Remove from pan. Fry the plantain in the same oil until it is well browned, approximately 10 minutes, over medium heat. Set aside. Fry the sesame seeds, stirring constantly over low heat, adding more oil if needed. When the sesame seeds start to brown, about 5 minutes, add the pecans and brown for 2 minutes more. Remove all from the pan, let cool, and grind finely in a spice grinder. It takes a bit of time, but this is the only way to grind the seeds and nuts finely enough.
Wipe out the frying pan and fry the tomatoes, tomatillos, thyme, and oregano over medium to high heat, allowing the juices to almost evaporate, about 15 minutes. Blend well, using 1/2 cup of reserved stock if needed to blend and set aside. Place the nuts, bread, plantains, raisins, onion, garlic and spices in the blender in small batches, and blend well, adding about 1 cup of stock to make it smooth.
In a heavy 4-quart stockpot, heat 2 tablespoons of lard or oil until smoking and fry the chile paste over medium to low heat, stirring constantly so it will not burn, approximately 20 minutes. When it is dry, add the tomato puree and fry until the liquid has evaporated, about 10 minutes. Add the ground ingredients, including the sesame seed paste, to the pot. Stir constantly with a wooden soon until well-incorporated, about 10 minutes. Add 1 cup chicken stock to the mole, stir well, and allow to cook 20 minutes, stirring occasionally.
Break up the chocolate and add to the pot, stirring until it is melted and incorporated into the mixture.
Toast the avocado leaf briefly over the flame if you have a gas range or in a dry frying pan and then add it to the pot. Slowly add more stock to the mole, as it will keep thickening as it cooks. Add enough salt to bring out the flavor. Let simmer another 30 minutes, stirring occasionally so it does not stick, adding stock as needed. The mole should not be thick; just thick enough to coat the back of a spoon.
Place the cooked chicken pieces in the leftover stock in a saucepan and heat through.
To serve, place a piece of chicken in a shallow bowl and ladle 3/4 of a cup of mole sauce over to cover it completely. Serve immediately with lots of hot corn tortillas.
You can use oil instead of lard to fry the mole, but the flavor will change dramatically. In our pueblo, people traditionally use turkey instead of chicken, and sometimes add pieces of pork and beef to enhance the flavor. You can use leftover mole and chicken meat to make Enmoladas or Tamales Oazaquenos made with banana leaves.
Inspired by Maria Taboada and Paula Martinez
Be sure to put the blended chiles through a sieve or food mill, or you will have pieces of chile skin in your mole, which needs to be silky smooth.
Recipe excerpted from Seasons of My Heart: A Culinary Journey through Oaxaca, Mexico by Susana Trilling: Ballantine Books, 1999