In a large bowl, combine the shredded chicken, 2/3 cups of sauce, sour cream (or lebneh), cumin, and 1 cup of the cheese.
Butter a large glass dish. Break the tortillas into large pieces and spread half of them on the bottom of the baking dish.
Spread half of the chicken mixture over the tortillas.
Layer remaining tortillas over the top, and spoon over the remaining chicken mixture.
Sprinkle the remaining cup of cheese over the top. Bake at 350°F (175°C) for 20-25 minutes, until top is golden and cheese is melted.
Sprinkle fresh tomato and cilantro over the top as garnish. Let the dish sit for about 5 minutes before serving. Enjoy!