Preheat oven to 350˚F and spray a 9x13 inch baking dish, or line with parchment.
In a skillet saute onion with butter until soft. Add cream cheese, 2 Tablespoons green chilis, 1 teaspoon cumin, and ¼ cup optional cilantro. Heat until melted and smooth. Stir in chicken.
In a small bowl combine cream of chicken soup, sour cream, remaining green chilis, and 1 teaspoon cumin.
Using a ½ measuring cup, scoop chicken mixture onto a flour tortilla. Add about 2 Tablespoons shredded cheese, then roll up and place in baking dish. Repeat for remaining tortillas.
Spread soup mixture evenly over the top of the tortillas, and sprinkle with remaining cheese. Cover with non stick foil or foil that has been sprayed with cooking spray.
Bake for 30-40 minutes, then uncover and bake 15-20 minutes longer until bubbly. Broil for 2 minutes if needed. Garnish with optional cilantro.
Allow to rest for 5 minutes before serving.