Preheat oven to 400°F.
In a medium saucepan, add tomatoes, green chiles, onion and chicken broth.
Place saucepan over medium heat and bring to a boil. Reduce heat, cover and simmer 25 minutes or until vegetables are tender.
Add 1/2 teaspoon salt and chopped jalapeño. Stir to mix.
While tomato mixture is simmering, place chicken breasts in a medium saucepan.
Add just enough lightly salted water to cover breasts.
Place saucepan over medium heat and bring to a boil. Reduce heat, and simmer for 10 minutes. Drain water from pan and keep chicken breasts warm.
In yet another pan, add flour, oil, chile powder and salt. Stir into a smooth mixture.
Gradually add 2 cups of water, stirring constantly so that mixture remains smooth.
Place saucepan over medium heat and bring to a boil, stirring occasionally. Reduce heat and simmer for 5 minutes.
Pour flour/chile powder sauce into a 9-inch square baking dish.
Place chicken breasts on top.
Pour the tomato and green chile mixture over the chicken.
Sprinkle with the grated cheese.
Place in preheated oven and bake for 20 minutes until chicken is tender.
Remove from oven and serve hot.