Preheat oven to 400° F (200°C).
Heat the olive oil in a large skillet over medium-high heat. Add the garlic and cook until fragrant.
Stir in the chiles, salt, and pepper. Cook for about 3 minutes.
Add 1 cup of the chicken stock to the pan. Mix well and simmer until the stock reduces by about a third.
Add the last cup of chicken stock to the pan and heat until warm. Set the sauce aside.
Meanwhile, lightly grease a 13" x 9" baking dish or cover in foil to help with clean up later.
While the sauce is simmering, shred the chicken into a bowl. Add 1 cup of the cheese and mix together.
Dip the tortillas into the warmed chicken stock until pliable, working 2 to 3 at a time so they don't stick together, then lay them on your work surface.
Add about 1/2 cup of the chicken and cheese mix down the center of each tortilla. Roll up around the filling and place seam side down in the baking dish.
Pour the chile sauce over the enchiladas. Top with the reserved 1 cup of cheese. Don't worry about full coverage, exposed tortilla edges crisp up in the oven.
Bake in the oven until the cheese is bubbling and brown, about 25 minutes, If you'd like extra browning, turn the oven to broil - watch carefully as not to burn.
Remove from the oven and allow to rest for about 5 minutes. Then serve with sour cream, Greek yogurt, or Avocado Crema.
Makes 8 to 10 servings.