Preheat a large skillet to medium heat with a drizzle of oil. Add the onion, bell pepper, and celery and sauté for about 5 minutes to soften.
Add the salt, cumin, and chili powder and stir to coat the veggies for about 3 minutes more. When the veggies are soft, turn the heat OFF the skillet.
Add the chicken, cream of chicken soup, chilis, half the cheese (2 ounces) and half the sour cream (⅓ cup) to the skillet. Stir to combine and taste; add more salt until very flavorful. This is the enchilada filling.
In a separate bowl, whisk together the remaining sour cream and the salsa verde with a pinch of salt.
Build the enchiladas. Prepare a 9x13 baking dish (or similar) with cooking spray. Spoon about half a cup of the filling into a tortilla, then roll up (it’s ok if the edges are open, we aren’t making burritos) and place seam side down in the baking dish.
Repeat with the rest of the tortillas and the filling, pressing the enchiladas together to fill every space of the baking dish. Save any leftover tortillas or filling.
Pour the green sauce over the enchiladas and top with the rest of the cheese. To this point, the recipe can be made in advance.
Bake the enchiladas at 375F for 30 minutes uncovered until hot and bubbly and slightly golden on top. YUM.