combine the tomatoes,green chiles,onion and chickenbroth in a medium saucepan, and bring to a boil over medium heat. reduce heat, cover and simmer 25 minutes until vegetables are tender. add 1/2 teaspoon salt and chopped jalepeno.
meanwhile, put the chicken breasts in a medium saucepan and cover with lightly salted water. bring to a boil, reduce heat, heat and simmer for 10 minutes. drain water from pan and keep chicken breast warm.
In yet another pan, blend the flour,oil,chile powder and salt into a smooth mixture. Gradually add the 2 cups of water, stirring constantly so that the mixture remains smooth. Bring mixture to a boil, stirring occasionally,then lower heat and simmer for 5 minutes.
pour sauce into a 9-inch square baking dish (pyrex if have one). Place the chicken breasts ontoop. pour the tomato and green chile mixture over the chicken. Sprinkle with the grated cheese and bake for 20 minutes until chicken is tender