Preheat your oven to 375°F (190°C) and lightly grease an 8x8 or 9x9-inch square baking dish. Combine all the taco seasoning ingredients in a small cup or container and set aside.
Spread 2 to 3 tablespoons of your smooth tomato sauce across the bottom of the empty dish to prevent sticking and create a moisture barrier.
Lay your first tortilla flat over the bottom sauce layer, using clean kitchen shears to trim it or cut it in half to patch together a level, flat sheet if your tortillas are large.
Brown your ground turkey in a skillet over medium heat and drain away any excess fat.
Sprinkle the combined taco seasoning ingredients (from step 1) and 1/3 cup of water directly over the browned meat.
Simmer the meat and spices over medium-low heat for 2 to 3 minutes until the liquid reduces completely and forms a thick, rich glaze that coats the meat.
Spoon a third of your seasoned ground meat evenly over the base tortilla layer in your baking dish.
Sprinkle a handful of rinsed and drained beans over the meat, drizzle with a few spoonfuls of tomato sauce (3-4 tbsp) and sprinkle generously with a handful of shredded cheese.
Place your second tortilla flat over the cheese layer and repeat the exact same pattern: meat, beans, a drizzle of sauce, and cheese.
Add your third tortilla and repeat the layers one final time.
Place your final tortilla on top of the casserole and spread the remaining smooth tomato sauce evenly over the entire surface to lock in moisture during baking.
Completely cover the top sauce layer with your remaining shredded Mexican blend cheese.
Place the dish onto the center rack of your oven and bake at 375°F (190°C) for 15 to 20 minutes until the edges are golden-crisp, the sauce is bubbling, and the cheese is fully melted and gooey.
Remove from the oven and let the casserole rest on the counter for 5 minutes so the lasagna-style layers set up properly before slicing into thick squares and serving warm.