Preheat the oven to 350 degrees F. Spray a 8x11-inch baking dish with nonstick cooking spray; set aside.
Add ground beef and onion to a large skillet over medium-high heat and cook for 6-8 minutes, breaking up meat, until meat is cooked through and onion is tender. Add garlic and cook for an additional minute. Drain excess grease.
Return skillet to heat and add taco seasoning, salt, pepper, beans and stir to combine.
Spread 1/2 cup enchilada sauce in the bottom of prepared pan. Top with a layer of 4 tortillas, 1/3 meat mixture and 2/3 cup shredded cheese. Repeat layers two more times.
Cover with foil and bake for 30 minutes, then remove foil and bake an additional 10 minutes.