Makes 8 servings
Position a rack in the center of the oven. Preheat oven to 400°F. Butter a 13 x 9-inch baking pan or other shallow baking dish.
Prepare Creamed Chicken or Turkey (recipe follows).
Stir in chili peppers and cumin.
In the prepared pan, layer the Creamed Chicken or Turkey alternately with tortilla chips and Cheddar cheese. Top with final layer of tortilla chips, and sprinkle with cheese.
Bake in 400°F oven until the sauce is bubbly and the cheese is golden brown, 25 to 35 minutes.
Melt butter in a large saucepan over medium-low heat. Add flour and whisk until smooth.
Cook, whisking constantly, for 1 minute. Remove the pan from heat. Add chicken stock and whole milk, whisking until smooth.
Increase the heat to medium and bring the mixture just to a simmer, whisking constantly. Remove the pan from the heat; scrape the corners and sides of the saucepan with a wooden spoon or heatproof rubber spatula, and whisk hard to break up any lumps. Return the pan to the heat and, whisking, bring to a simmer and cook for 1 minute.
Stir in chicken or turkey and sherry (optional). Cook for 1 minute longer. Remove from the heat and season to taste with lemon juice, salt, pepper and nutmeg.