In a medium skillet set over medium heat, add olive oil. When the oil is hot, add the onion, cook for 2 minutes, then add the poblano. Cook for an additional 2 minutes, then add the corn and continue cooking for 3-4 minutes. Remove from the heat, stir in chicken, seasonings, and 2 cups of cheese; set aside.
In a medium saucepan set over medium heat, melt butter. Add the flour and cook for 1 minute, whisking to prevent the flour from burning. Slowly pour in the milk, whisk until thickened, about 30 seconds. Add the sour cream, chicken broth, salt, cumin, garlic powder, paprika and cayenne pepper. Whisk and allow to simmer for 3-4 minutes or until it thickens. Remove from the heat and pour about 1/4 cup of the sauce into the chicken mixture.
Pour about 2 tablespoons into the bottom of a 9x13-inch baking dish, set the remaining sauce aside.
Warm the tortillas in the microwave for a few seconds so that they don't crack when rolled (or fry them if desired). Divide the filling between the tortillas, and roll them, placing them seam side down in the dish. Pour the remaining sauce over top, sprinkle with remaining cheese and green onions.
Place in the oven to bake for 30 minutes or until the sauce bubbles and the top turns golden brown. remove from the oven and garnish with chopped cilantro, if desired.
Notes
Pulled rotisserie chicken would be excellent in this recipe! -You can easily swap out the corn tortillas for flour, however you'll probably only need 12 instead of 14. -Try frying the tortillas for crispier enchiladas!