Bring a saucepan of water to a boil (about 3 cups).
Cut the stems from the chilis and remove most of the seeds inside. It's okay if you tear the chilis open to help get rid of seeds.
8 ancho chilis, 6 guajillo chilis, 2 morita chilis
Place the chilis in a heat-proof bowl and pour the boiling water over them. Place a small plate (or anything heat-proof) over the top of the chilis to help keep them all submerged. Allow them to soak for 30 minutes.
boiling water
While the chilis are soaking, turn your grill to medium-high. Place the tortilla over direct heat and cooked until dried out and browned in places. Turn off the grill and bring the cooked tortilla inside. (This can also be done over a gas stove or under the broiler).
1 corn tortilla
Drain the chilis into a colander over another heatproof bowl, reserving the soaking liquid.
Transfer the soaked chilis to a blender and pulse several times, using a small spatula to scrape down the edges and un-lodge any pieces that might have gotten caught in the blade. Add the oregano, ground cloves, and about ½ cup of the soaking liquid and purée again. The mixture should be very thick. Add another ½ cup soaking liquid and purée again. The mixture should not be runny, but almost like a paste.
1 tsp oregano, ½ tsp ground cloves
Transfer the chili purée to a sieve over a bowl. Use a wooden spatula to press the chili mixture through. Keep pressing until everything but the skins have passed through. You should have about 1 to 1¼ cups of the chili purée. Set aside. Clean out the blender vessel and place on its base.
Heat 2 tbsp vegetable oil in a large skillet (preferably cast iron) over medium heat. Once the oil is shimmering, gently place the onions and garlic in the center of the skillet and let cook for 4 minutes, gently pushing around with a wooden spoon (but not too much).
3 tbsp olive oil, ½ cup onion, 4 cloves garlic
Place the following ingredients around the onion and garlic in the hot oil: Almonds, pecans, anise seeds, peppercorns, cinnamon stick, allspice berries, raisins, and banana slices. Cook for another 4 minutes, until very fragrant and the onion slices are slightly charred on the edges.
1 tbsp almonds, 1 tbsp pecans, 1 tsp anise seeds, 1 tsp whole black peppercorns, 1 cinnamon stick, ½ tsp allspice berries, 2 tbsp raisins, 3 slices banana
Use a large spoon to scoop up and transfer the lightly fried skillet ingredients into the cleaned blender. Once all has been transferred, pulse the blender a few times. Use a spatula to scrape the edges and pulse again.
Add 1 cup chicken broth, close the lid to the blender, and purée again until smooth, about 1 minute. Break up the tortilla and add to the blender along with the tomatoes. Purée for another minute. The mixture will be light brown and somewhat thin.
4 cups chicken stock, ½ cup whole tomatoes
Meanwhile, clean out the large skillet. Then, over medium heat, heat the remaining 1 tbsp vegetable oil. Add the chili purée and cook, stirring often for about 2 minutes. Stir in the thin mixture from the blender. Keep stirring until fully mixed. The color should turn to a deep burnt orange or brown.
Stir in the chocolate and mix until fully melted. Stir in the brown sugar and salt. Continue cooking (stirring often) for 1 hour, adding more chicken stock to maintain a velvety sauce consistency (usually about 3 cups of stock over the hour). The sauce is now ready to use or store in an airtight container in the refrigerator for up to 7 days.
2 oz Mexican chocolate, 1 tbsp brown sugar, 1½ tsp salt