Wash the chile, remove stem and seeds. Place in a medium bowl and cover with warm water. Let stand for 30 minutes. While chile is soaking, add the sesame seeds and spices to a large skillet and toast over moderately low heat, stirring until fragrant. Place toasted mixture in a grinder and process to a fine powder. Set aside.
In the same skillet add in 1 tablespoon oil and warm slightly. Stir in raisins, almonds and tortilla. Cook over low heat until almonds are toasted and raisins plump. Transfer to a large bowl and set aside.
Add the tomatoes to the skillet and cook, turning frequently until skins are blistered on all sides. Transfer to a bowl. Add onion and garlic to the skillet and cook, stirring until lightly browned taking care not to burn the garlic. Place contents in a blender or food processor container and lightly chop.
Add a tablespoon of oil to skillet, stir in chopped vegetables and spice mix. Cover over medium heat until warmed through. Drain the chiles and add along with chicken stock. Partially cover, bring to a boil, reduce heat to simmer and cook for 1 hour. Remove from heat, add in chocolate and process in a blender in batches or using stick blender process until smooth. Season to taste with salt and pepper.
Preheat oven to 350 degrees. In a large skillet warm 2 tablespoons of oil and in batches if necessary brown chicken over high heat, turning as needed to brown all sides. Place browned chicken in oven proof dish, pour prepared mole over all. Cover and bake in preheated oven until chicken is cooked through, approximately 1 hour. Transfer to a serving platter and garnish with additional sesame seeds and chopped fresh cilantro.
Note: The mole can be prepared ahead of time and frozen in 2 cup portions. Defrost in refrigerator and warm before pouring over browned chicken. Bake chicken and mole as directed.