Prepare the enchilada sauce. If you're making it from scratch, follow your preferred recipe for homemade red enchilada sauce. If using store-bought, ensure you have about 15 ounces ready. A good sauce is the foundation of great enchiladas, so don't skimp on this step!

Sauté the beef filling. Heat 1 tablespoon of olive oil in a large sauté pan over medium-high heat. Add the diced white onion and minced garlic to the pan and sauté for about 3 minutes, stirring occasionally, until they become fragrant and softened. Next, add the lean ground beef and 1 teaspoon of ground cumin to the pan. Continue to sauté for about 5 minutes, or until the beef is completely browned, breaking it up with a wooden spoon as it cooks. Once the beef is browned, stir in the rinsed and drained pinto beans and the drained diced green chiles until everything is well combined. Season the mixture with a few generous pinches of fine sea salt and freshly-cracked black pepper to taste. Remove the pan from the heat and set aside.

Prep oven and baking dish. Preheat your oven to 350°F (180°C). Take a 9 x 13-inch baking dish and spread about 1/2 cup of the prepared enchilada sauce evenly along the bottom. This layer of sauce will prevent the tortillas from sticking and add an extra layer of flavor.

Assemble the enchiladas. Set up an assembly line with your tortillas, enchilada sauce, beef filling, and shredded cheese. Lay one large flour tortilla flat. Spread about two tablespoons of enchilada sauce evenly over the entire surface of the tortilla. Next, add a generous spoonful of the beef filling in a line down the center of the tortilla. Sprinkle about 1/3 cup of the Mexican-blend shredded cheese over the beef filling. Carefully roll up the tortilla, starting from one end, and place it seam-side down in the prepared baking dish. Repeat this process with the remaining tortillas and filling until your baking dish is full. Once all the enchiladas are assembled, spread any remaining enchilada sauce evenly over the top of the rolled enchiladas, ensuring they are fully covered. Finally, sprinkle any extra shredded cheese over the top of the sauce-covered enchiladas.

Bake to Perfection. Place the baking dish in the preheated oven and bake uncovered for 20 minutes, or until the enchiladas are cooked through, the cheese is melted and bubbly, and the tortillas are slightly crispy on the outside. The edges should be golden brown and the sauce should be simmering. Once baked, carefully transfer the baking dish to a wire rack and let it rest for a few minutes before serving. This allows the enchiladas to set slightly and makes them easier to serve.