Heat oven to 375°F. Coat a 13 x 9 x 2-inch baking dish with nonstick cooking spray.
Heat oil in a large nonstick skillet over medium-high heat. Add ground beef and onion. Cook for 5 minutes, until lightly browned. Add potato and tomato and cook, covered, about 5 to 7 minutes, or until potato softens.
Add beans, chili powder, salt and garlic powder. Mix until well combined and set aside.
Spread 1/4 cup of the enchilada sauce on bottom of baking dish. Tear up 8 of the tortillas and layer over sauce. Spoon on meat and bean mixture. Pour 1/2 cup enchilada sauce evenly over meat layer.
Tear up remaining 8 tortillas and layer over sauce. Pour remaining sauce over top and sprinkle with cheese.
Bake at 375°F for 25 minutes or until bubbly and cheese is melted.