Cut the chicken thigh meat into medium (1/2”) dice. In a cast iron or heavy bottomed skillet, heat the olive oil over medium heat and saute the onion for about 3 minutes. Add the chicken and chili powder, then season with salt and pepper. Saute another 5 minutes, then reduce heat, cover and let simmer another 15 minutes. Remove chicken mixture from heat and cool for 10 minutes; stir in sour cream and set aside.
Now begin the filling process. Warm the tortillas in the oven or on a flat griddle and spread them out on a clean counter top. Evenly distribute the chicken mixture, ½ of the cilantro and the roasted poblanos onto each tortilla, sprinkle with 1 tbsp shredded cheese on each, and roll each of them up. Coat a pyrex 13x9 pan with baking spray or butter, then arrange each rolled tortillas in the pan. Now preheat oven to 350 degrees.
Make the enchilada sauce by heating the tomato sauce, adding the adobo and finish by whisking in the cold butter. Salt and pepper to taste.
With the sauce, remaining shredded cheese and queso fresco, you can “stripe” the top of the enchiladas as you wish, then sprinkle the remaining cilantro evenly. Bake uncovered for 20 minute