1. Preheat oven to 350°F (175°C). Lightly grease a 9×13-inch baking dish.

2. In a skillet over medium heat, brown the ground beef until no longer pink. Add diced onion and cook until soft, about 3–4 minutes.

3. Drain excess grease, then add taco seasoning and 1/4 cup of water. Simmer for 3–5 minutes.

4. Stir in the can of diced tomatoes with green chilies and let simmer 2 more minutes.

5. Layer the bottom of the baking dish with half of the crushed Doritos.

6. Spoon half of the beef mixture over the chips, followed by half the sour cream and half the cheddar cheese.

7. Repeat the layers: remaining Doritos, beef mixture, sour cream, and cheese.

8. Bake uncovered for 20–25 minutes until cheese is melted and bubbly.

9. Let cool for 5–10 minutes before serving. Garnish with desired toppings.