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

2. In a large skillet over medium-high heat, cook the ground beef and diced onion until the beef is browned and the onion is soft. Drain any excess grease.

3. Stir in the minced garlic and cook for 30–60 seconds, just until fragrant.

4. Sprinkle the taco seasoning over the beef mixture, pour in the water or beef broth, and stir well. Simmer for 2–3 minutes, until slightly thickened.

5. Reduce the heat to low and stir in the drained Rotel, condensed cheddar or nacho cheese soup, and sour cream. Mix until smooth and creamy. Remove from the heat.

6. Spread half of the crushed Doritos evenly over the bottom of the prepared baking dish.

7. Spoon half of the creamy taco beef mixture over the Doritos, then sprinkle with about 1 cup of shredded cheese.

8. Add the remaining crushed Doritos in an even layer, top with the remaining beef mixture, and finish with the rest of the shredded cheese.

9. Bake for 18–22 minutes, or until the cheese is melted and the casserole is hot and bubbly around the edges.

10. Let the casserole rest for 5–10 minutes so it can set slightly.

11. Top with shredded lettuce, diced tomato, green onions or cilantro, jalapeños, salsa, and extra sour cream, if desired.

12. Scoop into bowls or onto plates and serve warm.