In a heavy 4-quart stockpot, boil about 1 1/2 quarts of water. Add the tomatoes and tomatillos and cook until they just change color, about 8 minutes. Reserving the water, remove the tomatoes and tomatillos to a colander, and when they are cool enough to handle, remove and discard the skins from the tomatoes. Set the tomatoes and tomatillos aside.
On a 10-inch dry comal, griddle or in a cast-iron frying pan, toast the chiles anchos over medium heat for about 2 minutes on each side, until the skins blister and bubble and they give off their aroma. Remove from the heat and place them in the leftover hot tomato water to soak for 20 minutes. Set aside.
In an 8-inch cast-iron frying pan, fry the sesame seeds in 1 tablespoon oil, over low heat for 10 minutes. Remove, let cool . Set aside. In the same frying pan, add 1 tablespoon oil, and fry the almonds, raisins, garlic, onions, cloves, cinnamon, peppercorns, oregano and thyme over medium heat until brown and the onion is transparent and aromatic. Set aside to cool.
Place the tomatoes, tomatillos, and soaked chiles in a blender with 1 cup of the chicken stock. Blend for 3 minutes. Pour the tomato and chile mixture through a food mill or sieve to remove any seeds and the chile skins. Set aside. Blend sesame seeds, the almonds, raisins, onion, garlic and seasonings in the blender with 1 1/2 cups chicken stock until smooth. Set aside.
In a heavy 6-quart pot, heat the remaining 2 tablespoons oil and brown the chicken pieces well, but do not cook them through, about 10 minutes. Remove from the pan. Pour off all but 1 1/2 tablespoons of the oil and fry the tomato and chile mixture with the seasoning mixture over medium heat for 10 minutes, stirring constantly. Add the ground sesame seeds and stir until well incorporated, about 10 minutes. Return the chicken to the bubbling sauce and continue cooking over low heat, covered, for 20 minutes more. Add the remaining 1 1/2 cups chicken stock, thinning it so that the sauce is just thick enough to coat the back of a spoon. Add the capers, caper juice and the olives to the sauce. Let the chicken simmer, covered, 15 minutes more.
Adjust sea salt to taste. Place the chiles serranos directly into the sauce just before serving or place in each bowl as a garnish. Serve immediately with fresh corn tortillas.
Hint: If the sesame seeds jump around a lot in the frying pan add a pinch of salt and keep stirring. We grind the sesame seeds by hand on a metate but you can also grind them in a spice grinder. It takes a bit of time, but it is the only way to grind them fine enough. If you don’t care if the sauce has a little texture, grind the seeds in a blender and strain through a wire-mesh strainer.
Susana Trilling © 1999 Seasons of My Heart, Oaxaca, Mexico