Preheat the oven to 350F. Grease an 8x8 baking dish and set it aside.
Heat the olive oil in a large skillet over medium heat. Once it's hot, add the peppers and onions. Cook, stirring often, until they begin to soften, about 3-5 minutes. Then add the garlic. Cook and stir a minute or so more, until fragrant.
Add the beef to the skillet. Cook, breaking it up as it cooks, until it is browned throughout. Drain any excess fat if needed. Add the pinto beans and taco seasoning and stir to incorporate everything. Remove the skillet from the heat.
Spread a layer of the enchilada sauce into the bottom of the baking dish, enough to coat the bottom. Arrange 4 of the tortilla halves around the dish.
Spread 1/3 of the meat mixture over the tortillas, about 1/2 cup of cheese, then another layer of enchilada sauce. Arrange 4 more tortilla halves over that, then continue to layer everything until all the meat is used up (you should get 3 layers).
After the last layer, add 4 more tortilla halves, then spread over the last of the enchilada sauce and sprinkle over the last 1/2 cup of cheese. Cover the dish with foil and bake for 20 minutes. Then remove the foil and bake an additional 15 minutes, until everything is heated through.
Let it sit for 5 or so minutes, then cut into it and serve.
