Step 1Place the turkey legs and thighs in a large stock pot with the onion, garlic, mint and 2 teaspoons salt. Cover with cold water and bring to a boil. Simmer the ingredients for an hour, until the turkey is tender and the stock is fragrant. Remove the turkey to a large plate and strain the stock, reserving both separately.
Step 2Meanwhile, clean and devein all the chiles, removing the seeds and stems. In batches, toast the chiles in a large saute pan or comal (griddle) until aromatic and lightly charred, about 5 minutes. Immerse the chiles in a large bowl of hot water, weighted under a large plate to keep them submerged. Soak 45 minutes to an hour, until softened.
Step 3Halve the tomatoes crosswise and place them, skin-side-up, on a foil-lined baking pan. Broil 2 to 3 minutes until the skin is blistered. Remove and reserve.
Step 4In a large pot or Dutch oven, heat 2 tablespoons of the oil over high heat. Add the plantain slices and fry until golden brown on both sides, about 3 minutes. Remove to a medium bowl and reserve.
Step 5Add another 2 tablespoons of the oil to the same pan and saute the sesame seeds, almonds, raisins, bread, thyme, cloves, pepper, marjoram and cinnamon, stirring constantly so they do not burn, for about 10 minutes.
Step 6Working in batches in a blender or food processor, blend the almond-raisin-spice mixture with the chiles, tomatoes and plantains, adding the reserved turkey stock as needed to the mixture until you have a fairly smooth paste. Reserve in a separate bowl.
Step 7Heat one-half cup of the oil in the large pot, then add the blended mixture. Cook the mole base over high heat for 30 minutes to meld and concentrate the flavors, scraping the bottom of the pan and stirring constantly to avoid burning (be careful, as the hot mixture splatters a bit as it cooks). Stir in the chocolate and continue cooking until it's melted. Remove from the heat; you will have about 6 cups mole base. Remove half the mole base from the pot and cool; seal tightly and refrigerate or freeze for another use.
Step 8Return the pot to high heat and whisk in enough reserved turkey stock to make a sauce the thickness of heavy cream. Season the sauce, stirring constantly as it cooks, with additional salt or chocolate, to sweeten.
Step 9Add the turkey pieces to the mole, spooning the sauce evenly over the meat (alternately, you can remove the meat and shred it before adding to the mole). Bring the sauce to a simmer and continue to cook to reheat the meat. Stir frequently, scraping the bottom to make sure it does not burn. Remove from the heat and serve immediately.