Heat oven to 350°F. Spray 13x9-inch (3-quart) glass baking dish with cooking spray.
In 2-quart saucepan, stir broth, flour, cumin and red pepper with whisk until blended. Cook and stir about 5 minutes, until mixture boils and thickens slightly. Remove from heat. Stir in yogurt until blended.
In medium bowl, mix chicken, 3/4 cup of the cheese, the corn, black beans, green onions, cilantro, chiles and 1/2 cup of the yogurt sauce. Spoon about 1/3 cup chicken mixture down center of each tortilla. Roll up tortillas; arrange seam sides down in baking dish. Top with remaining yogurt sauce. Cover with foil.
Bake 30 to 35 minutes or until sauce is bubbly. Sprinkle with remaining 3/4 cup cheese. Bake uncovered about 5 minutes longer or until cheese is melted. Top with tomato just before serving.