Preheat oven to 350 degrees. Add enchilada sauce, sour cream, and salsa verde to a large mixing bowl then whisk to combine. Add tortillas, chicken, and black beans then mix to combine.
Spray a 9x13 casserole dish with non-stick spray then pour the mixture inside. Top with cheese then bake for 20-25 minutes, or until golden brown and bubbly. Let rest 10 minutes before serving.
For the Pico de Gallo:
Combine tomatoes, green onions, cilantro, and the juice of half the lime into a bowl. Season with salt and pepper, then stir to combine. Taste, then add the juice from the second lime half if desired.