Mix your ground beef and onion in a skillet and cook until the meat is browned all the way through. Drain any excess grease.
Add one can of semi-drained red kidney beans to the cooked meat/onion mixture. I just poured off the top liquid. Add a can of Rotel tomatoes (or chopped tomatoes). Mix together.
Add your taco seasoning packet and cream of chicken soup (can use cream of mushroom if you prefer). Add your 1/2 cup of water and stir together.
Simmer 5-10 minutes, until everything is combined and starts to thicken.
Spray a 9x11 pan with cooking spray.
Put crushed taco chips on the bottom.
Add half of your meat mixture and top with half of your shredded cheese.
Repeat layers (chips, meat, cheese).
Cover with foil and cook in the oven at 325 degrees for 30 minutes or so, until top is bubbly.
You can top individual servings with sour cream and whatever else you like, such as more crushed chips or green onion tops.