Preheat the oven to 500°F.
In a 10 inch oven-safe skillet, heat oil over medium heat.
Adding onion, garlic, cumin, and salt and cook, stirring, leave for about 5 minutes, until the onion has softened.
Transfer the skillet mixture to a large bowl.
Add the enchilada sauce, sour cream, and 1/4 cup water to thebowl with the onion mixture and stir.
Add the tortillas, chicken, and beans until thoroughly coated.
Spoon the mixture into the skillet and cook over medium heat forabout 3 minutes. Sprinkle the cheese all over the top and bake for 5 minutes, until the cheese is bubbling.
Let cool slightly, then, if desired, top the enchiladas with sour cream, jalapeños, and cilantro and serve directly from the skillet at the table.