Preheat the oven to 325°F. In a large skillet over medium heat, cook the ground beef until browned, then drain the excess fat. Incorporate the beans, diced tomatoes with chilies, chopped onion, taco seasoning, cream of chicken soup, and water into the skillet. Allow the mixture to simmer over medium-low heat, stirring occasionally until thoroughly blended and warmed through.

Lightly grease a 9×13-inch casserole dish. Spread a layer of crushed tortilla chips on the bottom. Spoon half of the meat and bean mixture over the chips and sprinkle with one cup of shredded cheddar cheese. Repeat the layering with remaining chips, meat mixture, and cheese.

Cover the dish with aluminum foil and bake in the preheated oven for 20 to 30 minutes, until the casserole is heated through and bubbly.

Uncover and place the casserole under the broiler for a few minutes, just until the top layer of cheese begins to brown.

Allow the casserole to rest for 5 to 10 minutes before serving. Accompany each serving with a dollop of sour cream and a spoonful of salsa, if desired.