To prepare cornmeal pastry: Combine flour, cornmeal, and salt in medium-size bowl. With pastry blender or 2 knives, cut in butter until mixture resembles coarse crumbs.

Sprinkle cold water, 1 tablespoon at a time, over mixture, tossing lightly with fork after each addition until pastry is moist enough to hold together.

Shape pastry into a ball. Cover with plastic wrap and refrigerate until needed.

To prepare filling: Cook green onion, carrot, and chili powder in butter in 10" skillet over medium-high heat, stirring occasionally, until slightly softened, about 5 minutes.

Add flour; cook, stirring constantly, 1 minute or until smooth and bubbly.

Stir in milk and chicken broth; cook, stirring constantly, until mixture thickens, 1-2 minutes.

Stir in cooked chicken, black beans, corn kernels, green chiles, and salt. Spoon chicken mixture into 13" x 9" x 2" baking dish.

Roll pastry out on lightly floured surface with floured rolling pin into rectangle 1" larger than baking dish.

Center pastry over filling; fold overhang over pastry, pressing to form decorative edges. Using sharp knife, cut decorative vents in pastry.

Bake in preheated moderate oven (350 degrees) for 35-40 minutes or until pastry is golden and chicken mixture is heated through.