In a skillet, cook the ground pork and chopped onion over medium heat until the pork is browned and the onion is soft.
Add the cumin, chili powder, salt, and black pepper to the pork mixture. Stir well.
In a baking dish, layer half of the corn tortillas, followed by half of the pork mixture, half of the enchilada sauce, and half of the shredded cheese. Repeat the layers.
Bake in the preheated oven for 30-40 minutes, or until the cheese is melted and bubbly.
Let the casserole cool for a few minutes before serving.
Notes:
This casserole can be made ahead and refrigerated until ready to bake. Just add an extra 10 minutes to the baking time if baking from cold.