Chicken and Corn Tortilla Casserole

Ingredients:

• 4 skinless, boneless chicken breasts
• 1 cup chopped canned green chili peppers (drained)
• 1 medium onion, finely chopped
• 1 crushed clove of garlic
• 1 cup sour cream
• 1/2 tsp cumin
• 1/2 tsp salt
• 1/4 tsp pepper
• 3 tbsp. grated cheddar cheese
• Cooking spray
• Chicken gravy, see recipe below
• 24 corn tortillas (15 cm in diameter)

Chicken gravy:

• 6 tbsp (90 g) butter
• 6 tablespoons flour
• 1 cup chicken broth
• 1 cup of milk
• Salt and pepper

Preparation:

1. Place the chicken in a large saucepan, cover with water, and add a pinch of salt. Bring to a boil and simmer until tender, about 30 minutes.
   
   Remove the chicken from the pan and let it cool. Shred the chicken when it's cool enough to handle. Reserve 3 1/3 cups of broth (1 cup for gravy; if you don't have enough, use canned broth).
2. In a large saucepan, combine 2 1/3 cups of the reserved broth, chicken gravy, green chili, onion, garlic, sour cream, cumin, salt, and pepper. Bring the mixture to a boil, stirring constantly. Remove from heat.
3. Preheat oven to 350°F (180°C). Spray a 13x9-inch baking dish with cooking spray. Pour 1 cup of the mixture into the prepared dish. Top with a layer of 6 tortillas, then 1 cup of shredded chicken and 1/2 cup of cheddar cheese.
   
   Repeat the layers three more times, finishing with a layer of cheese. Spread the remaining mixture on top of the cheese. Make sure all the tortillas are completely covered by the other layers, otherwise they will become very tough during baking. Bake, uncovered, for 30 minutes.
4. Chicken gravy: In a medium saucepan, melt the butter and whisk in the flour. Cook over medium heat, whisking constantly, until the mixture begins to simmer and the flour turns light brown. Gradually stir in the chicken broth and milk and continue cooking, stirring, over medium heat. When the mixture thickens, about 5 minutes, season with salt and pepper.