Step 1

Melt the butter in a large sauté pan over medium heat. Add the onion, bell pepper, and garlic and sauté until soft, 5-10 minutes.

Step 2

Stir in the chili powder, cayenne, salt, and pepper and cook for 1 minute. Sprinkle in flour, 1/2 cup at a time, and stir until incorporated.

Step 3

Slowly whisk in 3 cups of the stock, about a cup at a time, until smooth.

Step 4

Whisk in cream and stir in chiles and tomatoes.

Step 5

Preheat the oven to Grease a 9-by-13-inch baking dish with butter.

Step 6

Pour a little of the sauce on the bottom of the casserole. Line the pan with half the tortillas, overlapping, cutting one or two in half or quarters to fill in the corners.

Step 7

Cover the tortillas with half the sauce. Add half the chicken and sprinkle with half of the cheese. Add a second layer of tortillas, the remaining sauce and chicken, and the rest of the cheese.

Step 8

Cover the casserole dish with non-stick foil (or spray regular foil with non-stick cooking spray).

Step 9

Bake for about 1 hour or until casserole is hot and cheese is melted.

Step 10

Uncover the dish for the last 15 minutes if you'd like to brown the cheese a bit.