To make the sauce, soak 3 dried New Mexico chiles (hot) and 3 dried Ancho chiles (mild) in 4 C. boiling water. When they are soft, save the liquid and remove the stems and seeds from the peppers. Puree the chiles and broth together.
Chop 1 bunch of spring onions, reserving the greens. Saute the onions in 2 T. olive oil until tender, then add 1 T. cumin and 1 t. coriander powder. Cook another 3 minutes. Add the chile sauce along with 3 diced canned tomatoes. Bring to a boil and simmer for 10 minutes. In a small bowl, combine 2 T. cornstarch with 1/2 C. water until smooth. Add to the sauce, stir in and cook until it thickens slightly.
(Alternately, you can use canned enchilada sauce).
Rinse 1 bunch of kale, remove the thick stems and chop roughly.
Pour a thin layer of the sauce over the bottom of a 9×13 casserole dish or a large cast iron skillet. Spread the kale over it, then season with salt.
Peel 1 butternut squash (carefully), then cut in half lengthwise and remove the seeds. Cut into 1/4″ thick half rounds.
Make one layer of squash. Sprinkle with salt, then cover with a layer of corn tortillas. You can either soak the tortillas in the sauce first, or drizzle sauce over them once they are in place. Make another layer of squash, then another of tortillas plus sauce. Repeat until the squash is all used up.
If there is sauce remaining, pour it in. Top with a layer of your favorite grated cheese. Bake at 350 until the enchiladas are bubbling and the cheese beginning to brown, then sprinkle the chopped onion leaves over and bake another 5 minutes.