A scant 1/8 teaspoon cloves, preferably freshly ground
1 ounce (about 1/4 of a 3.3 ounce tablet) Mexican chocolate, roughly chopped
1 slice firm white bread, darkly toasted and broken into several pieces
1/4 cup sugar (plus a little more if needed)
Salt
About 2 quarts chicken broth
12 good-size pieces of chicken—bone-in breast halves or leg-and-thigh pieces—trimmed of excess fat
1/3 cup sesame seeds
Procedure
1. Prepare the mole base: If your slow cooker has a removable cooking crock that can be placed directly on the heat, measure in the lard or oil and set it over medium heat. Otherwise, heat the lard or oil in a very large (7- to 8-quart) pot or Dutch oven. When hot, add the chiles, garlic, almonds and raisins. Stir slowly and continually until the chiles are thoroughly toasted (the interior of each piece will become lighter in color) and the almonds have taken on a creamy color and toasty aroma—about 5 minutes.
Add the tomatoes (with their juice), spices, chocolate and bread. Cook until the tomato juices are reduced and quite thick, about 2 minutes. Add 2 cups water, the sugar and 1 1/2 teaspoons salt. Stir to combine. When the liquid comes to a simmer, transfer the crock to the slow cooker (or scrape the mixture into your slow-cooker). Cook on low for 6 hours. After 6 hours most of the liquid will be reduced to a glaze. The mixture can hold for several hours on the slow cooker's "warm" setting.
2. Finish the mole: Scrape every bit of the mole base into a bowl, then scoop half of it into a blender jar. Add 2 cups of the chicken broth, cover and blend until as smooth as possible—for most household blenders this will take 4 to 5 minutes. Set a medium-mesh strainer over the slow-cooker's cooking crock and press the mole base through it. Repeat with the remainder of the mole base. Stir in 3 cups more chicken broth. Simmer in the slow-cooker for 2 hours or so on high. If the sauce has thickened past the consistency of a cream soup, stir in a little more of the broth. Taste and season with additional salt (usually about 1 teaspoon) and sugar (usually 2 to 3 tablespoons).
3. Grill the chicken: Light a gas grill, setting the temperature at medium on the sides, off in the center; or light a charcoal fire, letting the coals burn until they're covered with white ash and medium hot, then banking them to the sides. Sprinkle both sides of the chicken pieces liberally with salt, then lay them, skin side up, in the center of the grill. Cover and cook until the chicken is done (160°F on an instant-read thermometer or a small knife inserted into the thickest part of the thigh draws clear—not rosy—juices), 35 to 45 minutes. With this method of chicken grilling, there's no need to turn the chicken, only to move pieces on the edge around if they are browning more quickly than those in the middle. The internal temperature of the grill should stay at about 325°F.
4. Serve: In a small skillet over medium heat, toast the sesame seeds, stirring nearly constantly, until lightly browned and aromatic, about 4 minutes.
Lay a piece of grilled chicken on each dinner plate. Pour a generous 1/2 cup of sauce on and around the chicken, then sprinkle with a generous shower of sesame seeds. Serve right away.