Using rubber gloves, remove stems from dried chili peppers and discard, then remove seeds and membranes and set aside, saving the exteriors in a separate bowl. In a small sauté pan over medium heat, roast seeds and membranes until fragrant and slightly toasted and let cool. Using a spice grinder, grind until fine. Set aside.
In a small sauté pan over medium heat, toast 7 tablespoons sesame seeds until golden and let cool. Using a spice grinder, grind until fine. Set aside.
In a food processor or blender, purée garlic and ½ onion with ½ cup water and set aside. Melt chocolate in a double boiler over low heat and set aside.
Heat 2 tablespoons olive oil in a medium sauté pan over medium heat. Add raisins and almonds and cook until lightly browned. Drain from oil and purée in food processor until smooth. Place mixture in a large, heavy-bottomed pot or Dutch oven. Add breadcrumbs, spices, brown sugar, ground chili peppers and ground sesame seeds.
In a large pot of boiling water, blanch plantain pieces for 4 minutes. Remove from water, remove skin when cool enough to touch and purée, adding a few tablespoons of cooking water, or as needed, for a smooth, thick purée. Add purée to the large pot. Add onion purée and melted chocolate; mix all the ingredients well.
Return the plantain cooking water to a boil; quickly blanch the dried chili peppers long enough to soften. Drain from water using a slotted spoon and purée. Add a few tablespoons water, or as needed, for a thick, smooth purée.
In a large frying pain, heat remaining ½ cup olive oil. Add chili pepper purée, cook and stir until well combined (about 5 minutes). Remove from heat and add to large pot with remaining ingredients and stir gently. Add about 2 cups chicken broth. At this point you may want to blend your mole poblano to achieve a smooth consistency. (It should still be somewhat thick but add chicken broth as needed to facilitate puréeing.)
To poach turkey or chicken, cover with water in a large pot with remaining ½ onion and bring to a boil. Lower heat and simmer for about 15 minutes, until cooked through. Cut into serving-size pieces and reserve cooking broth.
In a saucepan over low to medium heat, using either the poaching broth or canned broth, thin a portion of the mole sauce just enough to make a velvety coating when poured over poultry. (Add liquid slowly to achieve the desired consistency.) Serve poultry hot, topped with toasted sesame seeds and warm tortillas and rice on the side. Refrigerate or freeze remaining mole poblano.
*Find in the Latino aisle at the supermarket.