Preheat the oven to 350*.
In a pan, brown the beef and chopped onions, drain.
Then add in the Velveeta cheese, milk, soups and enchilada sauce. Make sure the heat is on low so the milk mixture won't scald.
Let cook and stir until cheese is melted and all of the ingredients are combined.
Add half the bag of crushed tortilla chips into a 9 x 13 x 2" pan.
Pour the meat and cheese mixture over the crushed chips and then top with the other half of the chips.
Bake uncovered at 350 degrees for 45 to 50 minutes.
Serve the sides along with the casserole.
