Spray a 9 x 13 baking dish with nonstick cooking spray.
In a heavy skillet, over medium heat, warm olive oil, then add ground beef. Cook beef until completely browned.
Mix taco seasoning and pinto beans with cooked ground beef, continue cooking for approximately two more minutes.
Coat bottom of a baking dish with approximately 1/4 cup of enchilada sauce.
Layer about 1/3 of the corn tortillas over enchilada sauce, add 1/3 of meat and beans mix, followed by layer of cheese, sauce. Repeat the layers of corn tortillas, meat and beans, cheese and sauce, until all the ingredients are used.
Cover with aluminum foil and bake for 30 minutes. Remove foil and bake for 10 more minutes.
Top with diced tomatoes and green onions and serve hot.