1. Getting started. To ensure success and to streamline a rather complex preparation, first set out all the ingredients, completing basic preparations as described: husk and rinse the tomatillos, stem and seed dried chiles, peel the garlic, grind spices if you’re using whole, toast the bread and chop the chocolate.
Spread the tomatillos on a baking sheet and roast them 4 inches below a very hot broiler, until darkly roasted, even blackened in spots, about 5 minutes. Flip them over and roast the other side, 4 or 5 minutes, until splotchy-black, blistered and soft.
Set out 2 large bowls and scrape the tomatillos, juice and all, into one of them. Set out a pair of tongs and a slotted spoon.
2. Initial toasting and browning. In an ungreased small skillet set over medium heat, toast the sesame seeds, stirring constantly until golden, about 5 minutes. Scrape 2/3 of them in with the tomatillos; set the rest aside for garnish.
Set a large (8- to 9-quart) pot (preferably a Dutch oven or Mexican cazuela) over medium heat. Measure the lard or oil into the pot. Turn on an exhaust fan or open a window or door. Tear the chiles into flat pieces and, when the lard or oil is hot, fry the chiles, three or four at a time, flipping them nearly continually with the tongs, until their interior sides have changed to a lighter color, about 20 to 30 seconds total frying time. Don’t toast them so darkly that they begin to smoke—that will make the mole bitter. As they’re done, remove them to the empty bowl, being careful to drain as much fat as possible back into the pot. Cover the toasted chiles with hot tap water and place a small plate on them to keep them submerged. Let stand about 30 minutes.
Meanwhile, remove any stray chile seeds left in the fat. With the pot still on the heat, fry the garlic and almonds, stirring regularly until browned (the garlic should be soft, the almonds browned through), about 5 minutes. With the slotted spoon, remove to the tomatillo bowl, draining as much fat as possible back into the pot.
Now, add the raisins to the hot pot. Stir with your slotted spoon for 20 to 30 seconds, until they’ve puffed and browned slightly. Scoop them out, draining as much fat as possible back into the pot and add to the tomatillos.
Raise the temperature under the pot to medium-high. Sprinkle all sides of the turkey breast halves with salt, then lay one in the pot. Thoroughly brown it on all sides, about 10 minutes total. Remove to a clean plate; brown the other half in the same way. Cover and refrigerate if not completing Steps 3 and 4 within an hour or so. Set the pot aside.
3. Blending and straining. Use tongs to transfer the rehydrated chiles to a blender, leaving the soaking liquid behind. Taste the soaking liquid, and, if it is not bitter, measure 2 ½ cups into the blender. If it is, throw it away and measure in 2 ½ cups water. Blend the chiles to a smooth puree, adding a little extra water if necessary to keep the mixture moving through the blades. Press the chile mixture through a medium-mesh strainer back into the empty chile-soaking bowl.
Without washing the blender jar, scrape the tomatillo mixture into it. Add 1 cup water, along with the cinnamon, black pepper, optional anise, cloves, bread and chocolate. Blend to a smooth puree, again adding a little extra water if necessary to keep the mixture moving. Press through the strainer back into the tomatillo bowl.
4. Searing and simmering. Check the fat in the pot: if there’s more than a light coating over the bottom, pour off the excess; if the pot’s pretty dry, film the bottom with a little more lard or oil. Set over medium-high heat. When quite hot, scrape in the chile puree and stir nearly constantly until the mixture has darkened considerably and thickened to the consistency of tomato paste, 10 to 15 minutes. Add the tomatillo puree and continue stirring until once again the mixture has thickened to the consistency of tomato paste, another 5 to 10 minutes.
Add 6 cups water to the pot and stir to thoroughly combine. Partially cover, reduce the heat to medium-low and simmer gently, stirring occasionally, for 45 minutes. Check the consistency: the mole should be thick enough to coat a spoon, but not too thickly. If it’s too thin, simmer it briskly over medium to medium-high heat until a little thicker; if too thick, stir in a little water.
Taste and season with salt, usually about 1 3/4 teaspoons, and the sugar (if you’re new to seasoning mole, keep in mind that it’s a delicate balance of salty, sweet and spicy; it’s best to start with the minimum quantities I’ve suggested, then refine the seasoning just before serving).
5. Braising and serving the turkey. Heat the oven to 325º. Lay the turkey into the mole, cover (use foil if you’re working in a cazuela) and place in the oven. Cook until an instant-read thermometer placed in the center of the turkey breast registers 150º (there will be only the slightest hint of pink if you cut into it), about 40 minutes. If the turkey breast has been refrigerated before going into the hot pot of mole, allow an additional 10 to 15 minutes cooking time.
Remove the turkey from the mole and place on a cutting board. Cover with foil and let it stand at room temperature for 10 minutes. Slice the turkey ½-inch thick, then arrange the slices slightly overlapping on a large, deep, warm serving platter. If the mole has thickened beyond the consistency of a medium cream soup, thin it with a little water. Taste and season with a little more salt or sugar if you think necessary.
Ladle a generous amount (3 to 4 cups) of mole over or around the turkey slices and sprinkle with the reserved sesame seeds. Decorate the platter with sprigs of watercress or parsley, and you’re ready for a party.
Working Ahead: Mole can be successfully made ahead—even getting better with 2 or 3 days well-covered residence in the refrigerator. Though braising the turkey can be done a day ahead (cover and refrigerate it separately from the mole), that approach is not my first choice because it is difficult to reheat cooked turkey and not have it dry out. Instead complete the mole through the simmering (Step 4); cool, cover and refrigerate the mole and the browned, uncooked turkey breast separately for up to 3 days. Just before serving, warm the mole in the pot, nestle in the turkey breast, then braise and serve as described in Step 5. The turkey breast will be much juicier.