Cut the chiles and bell pepper in half lengthwise, and discard seeds and membranes. Place chile and bell pepper halves, skin sides up, on a foil-lined baking sheet, and flatten with hand. Broil for 5 minutes or until blackened, turning occasionally. Place in a zip-top plastic bag, and seal. Let stand 15 minutes; peel and chop chiles and bell pepper.
Heat oil in a large nonstick skillet over medium heat. Add mushrooms, onions, and garlic; sauté 5 minutes. Stir in flour, sage, cumin, and black pepper, and cook 2 minutes. Stir in chopped chiles and bell pepper, broth, and water; simmer 5 minutes or until thick, stirring constantly. Stir in cream cheese. Remove from heat; stir in Jack cheese and cilantro.
Preheat oven to 350°.
Spoon 1 cup mushroom sauce into an 11 x 7-inch baking dish coated with cooking spray; top with 6 tortilla halves, 3/4 cup chicken, and 1 cup sauce. Repeat layers twice, ending with sauce. Sprinkle with Romano. Cover and bake at 350° for 35 minutes or until bubbly. Let stand 10 minutes.