Heat a shallow dutch oven over medium heat. You can also use a nonstick pan but a Dutch Oven is preferred because you can go from stove top to broiler!
Add the olive oil to the dutch oven and heat for 1 minute.
Add the diced onions to the pan and cook over medium heat for 5-6minutes (until the onions have released some liquid and they are turning translucent.
Add the ground beef to the pan. Cook the beef until it turns brown and use a wooden spoon to break the beef up into crumbles. It will take 5-6minutes for the beef to brown.
Once the beef is fully cooked and browned, add the sea salt, garlic powder, paprika, and chili powder. Cook for 1-2 minutes, stirring the meat so everything is evenly seasoned.
Add the diced tomatoes with their liquid and the water to the beef. Let the beef and tomatoes simmer for 5 minutes over medium-high heat.
Remove the dutch oven from the stove and use a large spoon to move the seasoned ground beef into a large bowl.
You will build your casserole inside the dutch oven!
Turn the oven on to broil and let the oven preheat while you build the layers of the casserole.
Ladle out 1/4 Cup of the meat sauce onto the bottom of the dutch oven.
Layer 4 corn tortillas on top of the meat sauce. You might use more or less tortillas per layer; it will depend on the size of your dish.
Top the tortilla layer with 1/2 of the remaining meat sauce and top the meat with 1/4 Cup of the shredded cheese.
Top the cheese with another layer of tortillas, the rest of the meat, and the remainder of the shredded cheese.
Place the casserole under the broiler for 5-7 minutes or until the cheese is melted, browned, and bubbly.
Remove the casserole from the oven and let it sit for 5 minutes so you can cut out even, neat servings.
You can top the casserole with cilantro and serve with fresh guacamole, salsa, or sour cream!
If you’re on a time crunch, you can season the beef with 1 tsp salt and 1 tsp pepper and mix store bought enchilada sauce with the beef, omitting the following ingredients: garlic powder, chili powder, smoked paprika, diced tomatoes.