Blend the beans with the evaporated milk, chipotle pepper, and chicken bouillon cube until smooth.

Pour the sauce into a small pot with a little oil. Cook over medium heat, stirring constantly to prevent sticking. Once it comes to a boil, remove from heat.

Lightly fry the tortillas one by one in oil. It's okay if they get a little crispy; they will soften later.

In a medium baking dish, arrange a layer of 4 tortillas. Cover with some of the sauce, then add chicken, tomato, onion, and cheese. Add another layer of tortillas and repeat the process until you have three layers. For the top layer, just add sauce, tomato, onion, and cheese. Cover with aluminum foil and bake in a preheated oven at 350°F (180°C) for 30 minutes or until the cheese is melted and bubbly.

Serve with rice and salad if desired.