Adjust the oven rack to the middle position, and heat the oven to 450℉. Spray a 9x13-inch baking dish with nonstick spray.
Toast the tortillas, one at a time, in a 12-inch nonstick skillet over medium-high heat until lightly browned (about 20 seconds per side); transfer to a plate and cover with a dish towel.
Tear 8 toasted tortillas into pieces and add them to the bowl of a food processor. Add the tomatoes and their juice and ¾ cup of the broth and process until smooth; transfer to a large bowl. Add the beef to the skillet and cook over medium-high heat, breaking up the meat with a wooden spoon, until no longer pink, about 5 minutes. Drain the beef in a colander and then stir it into the processed tortilla mixture.
Add oil and onion to the empty skillet and cook over medium heat until softened, about 5 minutes. Stir in the garlic, chili powder and cumin and cook until fragrant (30 seconds). Stir in the tomato sauce and the remaining ¾ cup of broth and simmer until slightly thickened, 5 to 7 minutes; transfer to a separate bowl.
Add half of the tomato sauce mixture to the bowl with the beef. Then add 1½ cups Colby Jack, cilantro and tabasco to the beef mixture as well. Season it all with salt and pepper.
Arrange 6 toasted tortillas in the bottom of the prepared dish (overlapping slightly). Spread the beef mixture evenly into the dish, then top with the remaining 6 tortillas followed by the remaining tomato sauce mixture. Bake until the filling is bubbling around the edges (about 30 minutes). Sprinkle with the remaining 2½ cups of cheese and continue to bake until the cheese is browned, 15 to 20 minutes. Let the casserole cool for 20 minutes before serving.
Notes
Toast tortillas first for best texture
Let rest before slicing for clean servings
Use fresh cheese if possible
Great make-ahead meal
Adjust spice level with Tabasco
This recipe can easily be made gluten-free (just make sure all ingredients are GF)