Preheat oven to 375°F. Spray an 8 x 8 or 6.5 x 9-inch baking dish with nonstick spray. Set aside.
Melt butter in a medium skillet over medium heat. Add the onion and bell pepper. Cook for 4 to 5 minutes, until softened. Stir in garlic, chili powder, paprika, cumin, salt, and pepper. Cook for 1 minute. (See Tip 4)
Sprinkle in flour; stir constantly for 1 minute to remove the raw taste. Gradually whisk in chicken broth, stirring until smooth. Simmer for 3 to 4 minutes until thickened.
Stir in the drained tomatoes with green chiles and sour cream. Add ¾ cup of shredded cheese and stir until melted and smooth.
Fold in the chicken. Taste and adjust seasoning if necessary.
Layer half of the corn tortillas in the prepared dish. Spoon over half of the chicken mixture over the tortillas. Repeat the layers. Top with the remaining ¾ cup of shredded cheese and crushed tortilla chips. (See Tip 5)
Bake at 375°F for 25 to 30 minutes until bubbly and lightly golden. Let rest 5 to 10 minutes before serving.
Garnish with chopped parsley or green onions if desired and serve.
Yield: 4 servings.