Chicken in Oaxacan Black Mole (Pollo en Mole Negro)

3 small dried pasilla chiles
3 small dried mulatto chiles
1 1/2 cups boiling water
1/4 cup sesame seeds
3 whole cloves
1 (1-inch) piece stick cinnamon
1/4 teaspoon whole coriander seeds
1/8 teaspoon whole aniseed
1/4 cup lard or vegetable oil
1/4 cup whole unblanched almonds
1/4 cup raisins
6 whole chicken legs, with thighs attached
1/4 teaspoon salt
1/2 cup coarsely chopped white onion
2 cloves garlic
1 tablespoon tomato paste
1 1/2 ounces Mexican chocolate, coarsely grated
1 cup chicken stock or broth

Toast, seed, de-vein and rinse pasilla and mulatto chiles. Place in medium bowl with boiling water; let stand 1 hour.

Toast sesame seeds in dry heavy skillet over medium heat, stirring frequently, until golden, about 2 minutes. Remove from skillet.

Combine cloves, cinnamon stick, coriander seeds and aniseeds in skillet; toast over medium heat, stirring frequently, until they start to change color and become fragrant, 20 to 30 seconds. Remove from skillet.

Heat lard in 12-inch skillet over medium heat until hot. Add almonds; cook and stir until brown, 2 to 3 minutes. Remove with slotted spoon; drain on paper toweling. Add raisins; cook and stir until puffed, about 30 seconds. Remove with slotted spoon.

Sprinkle chicken with salt. Cook in lard over medium heat until brown, about 5 minutes per side; remove to plate. Remove all but 2 tablespoons lard from skillet.

Process raisins in blender until finely ground. Coarsely chop almonds; add to blender and process until finely ground. Add onion and garlic to blender; process until finely ground.

Process 2 tablespoons sesame seeds by pulsing in electric spice grinder to fine powder; add to blender. Process clove mixture in grinder to fine powder; add to blender. Add chiles, 1/3 cup of the soaking water and the tomato paste to blender; process until smooth. If mixture is too thick, add just as much remaining soaking water, 1 teaspoon at a time, needed to release blender blades.

Heat the lard in skillet over medium heat until hot; reduce heat to medium-low. Add chile mixture; cook, stirring constantly, 5 minutes. Add chocolate; cook and stir until melted, about 2 minutes. Gradually stir in stock; cook, stirring frequently, 5 minute.

Add chicken to skillet; reduce heat to low. Simmer, covered, turning occasionally, until tender, about 45 minutes.

Place chicken on serving plates; top with sauce and remaining sesame seeds. Garnish with tomato wedges and cilantro sprigs.