Preheat your oven to 350°F (175°C).
In a large skillet, heat olive oil and cook ground beef until browned. Drain any excess grease.
Add taco seasoning and water to the skillet. Stir to combine, then simmer for 5 minutes.
Stir in diced tomatoes with green chilies and remove from heat.
In a greased 9x13-inch baking dish, layer half of the tortilla pieces on the bottom.
Top with half the meat mixture, then spread half of the sour cream, and sprinkle with half the cheese.
Repeat the layers: tortillas, meat, sour cream, and cheese.
Bake for 20-25 minutes until cheese is melted and bubbly.
Let cool for a few minutes before serving.