Make the sauce. In a high-powered blender, measure the hot water using the ticks on the side of the blender container. Add the chiles and submerge. Let sit for 10 minutes. Once reconstituted, add the remaining sauce ingredients. Blend on high until smooth. This yields 4 cups. It can be made up to a month in advance and stored covered in the fridge.
Make the filling. Preheat the oven to 400°. Preheat a 10-inch cast-iron skillet on medium-high for 5 minutes. Meanwhile, prepare the bell pepper and onion. Add the pepper, onion, oil and salt; sauté until charred and softened, about 10 minutes.
Meanwhile, add the chicken, black beans, cheese and ¼ cup of the Ancho-lada Sauce to a large bowl. Stir in the sautéed pepper and onion. In a 12 x 10-inch enamel baking dish (or similar-sized glass or ceramic dish), add 1 cup sauce to thinly coat the bottom of the pan. Fill each tortilla with ½ cup of the filling. Roll the enchilada and place snuggly in the pan, seam side down. Repeat. These can be prepped up to a day before baking.
To cook, pour 1 cup of the sauce down the center of the pan. Spread the sauce toward the edges leaving about 1½-inch clear space. Tent a piece of foil over the pan to create steam.
Bake for 20 minutes. Remove the foil. Sprinkle with the cotija and bake for 10 minutes more. Sprinkle with the chopped cilantro and, if desired, the pepita seeds. Serve.
From The Minimalist Kitchen (Oxmoor House) by Melissa Coleman.