Preheat the oven to 375°F (190°C). Spray a 9-inch x 13-inch pan with cooking spray. Arrange halved corn tortillas to just cover the bottom of the dish. Add a layer of chicken, cheese and enchilada sauce. Repeat for two more layers being sure to end with a layer of tortillas topped with enchilada sauce and cheese.
Bake lasagna for 35 minutes until cheese is bubbly. Top with crumbled tortilla chips and bake for 25 minutes more until chips are toasted and lasagna is heated through.
Let the lasagna rest for 10 minutes before slicing. Serve with sliced radishes, cilantro and sour cream.