Preheat the oven to 325 degrees Fahrenheit.
In a large skillet, brown the ground beef. Drain off any fat.
Stir in the beans, Ro-tel tomatoes, chopped onion, taco seasoning, cream of chicken soup, and water. Let this simmer over medium-low heat until everything is well combined and heated through.
Grease a 9×13 casserole dish.
Start layering! First, put down a layer of crushed tortilla chips, then a layer of the meat and bean mixture, followed by half of the shredded cheddar cheese.
Repeat the layers with more tortilla chips, the remaining meat mixture, and finally top with the rest of the cheddar cheese.
Cover the dish with foil and bake for 20-30 minutes, or until bubbly.
Let it sit for 5-10 minutes before serving. Top with sour cream and salsa for extra flavor!