Cheesy Chicken Enchiladas with Red Sauce

Are you ready to taste the best chicken enchiladas of your life? Although grilled chicken can be used to make this cheesy enchilada, roasting chicken breasts in a liquid with an exquisite taste allows you to get juicy and tender meat (which does not dry out during baking) and gives the dish another layer of flavor. The key to successful cooking is temperature control; you want the cooking liquid to never come to a boil. In fact, you should aim to keep the water temperature so that it releases thin trickles of steam from the surface, but never bubbles, throughout the cooking process. (It's not nearly as hard as it sounds.) You should also buy chicken breasts that are about the same size, so that they cook at the same speed. While the overall cooking time for this recipe doesn't quite match what you might call “fast,” cooking and assembling this dish with another kitchen helper is fun. Prepare a skillet (or two, so you have one for the freezer!) on Sunday, to enjoy the start of a new week. Homemade enchilada sauce with smoky ancho chili and a small amount of baking liquid is another highlight of this dish. However, if you want to save time on cooking, you can replace it with a store-bought sauce. And if you prefer to use the grill or leftover chicken as a quick fix, but still want to make the sauce from scratch, just replace the necessary liquid with water and / or chicken broth.
Preheat the oven to 400°F. Combine the stock, half the onion, and 4 sprigs of oregano in a medium saucepan over medium-high heat; bring to a boil.Add the chicken to the skillet; reduce the heat to medium-low and keep the liquid temperature between 160 ° F and 180 °F. When cooking. Cook the chicken until the thermometer set in the thickest part reads 160 ° F, 25 to 30 minutes. (It is important to maintain the temperature of the cooking liquid. You want them to steam, but not bubble at all.)Remove the chicken from the cooking liquid and allow to cool for 15 minutes. Chop the chicken. Leave 2 cups of the liquid to cook.Finely chop the remaining half of the onion (about 3/4 cup). Combine the tomato sauce, ground chili pepper, garlic, flour, cumin, salt, chopped onion, and remaining 2 cups cooking liquid in a medium saucepan over high heat; bring to a boil. Cook, stirring frequently, until thickened, 1-2 minutes. Leave 2 cups of the tomato mixture. Add the chopped chicken and beans to the remaining tomato mixture in the pan; stir to coat.Place about 1/3 cup of the chicken mixture in the center of each tortilla and roll up. Place the rolled tortillas seam-side down in a 13-inch x 9-inch glass or ceramic baking dish coated with cooking spray. Spread the remaining 2 cups of tomato mixture evenly on top; sprinkle with cheese. Bake in the preheated oven until the cheese melts and the sauce begins to bubble, about 20 minutes. Top with sliced tomatoes, avocado and the remaining 2 sprigs of oregano (about 2 tablespoons each). Drizzle with sour cream.