Preheat your oven to 375°F (190°C). Lightly grease a 9×13 inch baking dish with non-stick cooking spray to prevent the tortillas from sticking to the bottom.
In a large mixing bowl, combine the shredded chicken, Greek yogurt, diced onion, minced garlic, cumin, black beans, and corn. Stir in half a cup of the enchilada sauce to keep the mixture moist. Mix until everything is evenly coated.
Spread about 1/4 cup of the enchilada sauce on the bottom of the prepared baking dish. Lay half of the tortilla pieces over the sauce, creating an even layer that covers the bottom.
Spread the entire chicken and yogurt mixture over the first layer of tortillas. Sprinkle half of the shredded cheese over the chicken mixture. Pour half of the remaining enchilada sauce over the top.
Place the remaining tortilla pieces over the filling. Top with the rest of the enchilada sauce and the remaining shredded cheese. Ensure the cheese covers the edges so they get crispy.
Bake in the preheated oven for 25 to 30 minutes, or until the cheese is bubbly and starting to brown slightly. Remove from the oven and let it rest for 5 minutes before slicing.