Preheat oven to 400ºF and lightly grease a 9x13” (or similar sized) baking dish.
Heat oil over medium-high heat in a large skillet. Add turkey, and cook until no longer pink. Add peppers and onion, and cook until beginning to soften, about 5 minutes. Add taco seasoning and a big pinch of salt and pepper and cook for 1 more minute. Set aside until ready to assemble.
Heat salsa, beans and spinach in a saucepan until spinach has wilted. Set aside until ready to assemble.
Whisk together eggs, 1 teaspoon taco seasoning, hot sauce and a big pinch of salt and pepper in a large bowl.
Now it’s time to assemble the layers: First, place a layer of tortilla chips in the bottom of the baking dish, as close together as possible, overlapping where necessary. Next, layer half of the turkey mixture, then half of the salsa mixture, then half of the egg mixture, and finally top with half of the shredded cheese. Repeat these layers one more time, ending with the remaining cheddar cheese on top.
Bake in the preheated oven in the middle for 30 minutes uncovered, until the casserole is puffy throughout.
Let cool for 10 minutes before slicing and serving.
Top with desired garnishes, such as avocado, sliced jalapenos, cilantro, hot sauce or diced tomatoes.