Commence by setting the oven to a temperature of 350°F. Thoroughly grease a baking dish suitable for enchiladas.

In a medium-sized mixing bowl, amalgamate the finely shredded chicken, 1 cup of mozzarella cheese, and the green enchilada sauce. Stir until the ingredients are uniformly distributed.

Lay out a tortilla and spread approximately ¼ cup of the aforementioned chicken mixture uniformly across its surface. Roll the tortilla carefully, ensuring the filling remains inside, and place it into the prepared baking dish. Continue this process with the remaining tortillas.

For the white sauce: In a saucepan, melt the butter over medium heat. Subsequently, incorporate the flour, whisking continuously to prevent lumps from forming. Once combined, slowly introduce the chicken broth, continuing to whisk until the mixture is homogenous and begins to thicken. At this juncture, incorporate the sour cream and green chiles into the saucepan. Remove the saucepan from the heat once the ingredients are thoroughly mixed. Assess the seasoning and make adjustments using salt and pepper if necessary.

Pour the prepared white sauce over the enchiladas, ensuring they are uniformly coated. Sprinkle the enchiladas with the remaining mozzarella cheese.

Position the baking dish in the preheated oven and allow it to cook for a duration of 22 to 25 minutes. The enchiladas should exhibit a golden-brown hue on top, and the sauce should be bubbling upon completion.

Upon removing from the oven, garnish the enchiladas with freshly chopped parsley. Serve promptly.