Preheat the oven to 425 degrees F.
Preheat a large skillet over medium high heat. Add 2 tablespoons extra-virgin olive oil - twice around the pan. Add chicken and season with chili powder, cumin, and red onion. Brown the meat, 5 minutes. Add taco sauce or stewed or fire roasted tomatoes. Add black beans and corn. Heat the mixture through, 2 to 3 minutes then season with salt, to your taste.
Coat a shallow baking dish with remaining extra-virgin olive oil, about 1 tablespoon oil. Cut the tortillas in half or quarters to make them easy to layer with. Build lasagna in layers of meat and beans, then tortillas, then cheese. Repeat: meat, tortilla, cheese again. Bake lasagna 12 to 15 minutes until cheese is brown and bubbly. Top with the scallions and serve.