Preheat your oven to 350 degrees. Prep by mincing the garlic and chopping the bell peppers, jalapeño, and onions. Be sure to remove the jalapeño seeds. Next, spray a baking dish with nonstick spray and set it aside.
Heat the avocado oil in a large skillet over medium heat. Once it is warm, add the onions and bell peppers and cook, stirring occasionally, for 4-5 minutes. Add the jalapeño and minced garlic and cook for another 2 minutes.
Add the ground beef and taco seasoning to the skillet. Using a spatula, break the beef into smaller pieces, stirring it until it is fully browned, about 5 minutes.
Transfer the contents of the skillet to a large bowl. Add the diced green chiles, tomatoes, eggs, and salsa and stir until the ingredients are well combined.
Begin building and layering your casserole. Add a large scoop of the bowl's contents to the bottom of your greased baking dish. Top with one tortilla. Repeat until the mixture in the bowl is gone, smoothing during each step. You'll want to end with the mixture, not a tortilla.
Bake for 1 hour. Then add a cup of cheese to the top and bake for an additional 15 minutes or until the cheese is melted and the casserole is no longer wobbly in the middle. Remove the dish from the heat and let it rest for 5-10 minutes.
Chop the iceberg lettuce and cilantro and cube the avocado. Garnish the casserole with these toppings, and then add a pinch of salt if you would like. Serve immediately and enjoy.
It's best to place a baking sheet underneath the casserole dish in the oven; that way, your oven is protected if your casserole bubbles over during the baking process.
For a thinner, longer taco bake, consider using a 9-inch-by-13-inch pan. Layer with 1 1/2 or 2 tortillas, and subtract 15 minutes from the cooking time.