In a large pot combine chicken broth, 2 1/4 cups of the milk, the diced green chiles, oregano, garlic powder, and salt. Bring to boiling. Gradually add polenta or coarse cornmeal, stirring constantly. Reduce heat to low. Cook, uncovered, for 5 to 10 minutes or until thickened. Stir in corn and and queso Chihuahua. Add enough of the remaining milk to reach desired consistency. Remove from heat. Let stand for 5 minutes before serving.