Preheat your oven to 375°F and lightly grease a 9x13 inch baking dish.
In a large skillet, brown the ground beef and onion over medium heat until the beef is fully cooked. Drain the grease.
Add the minced garlic and chili seasoning, stirring for 1 minute.
Stir in the pinto beans and enchilada sauce. Simmer for 5 minutes until the mixture thickens.
Place half of the Fritos in an even layer at the bottom of the prepared baking dish.
Spread the meat mixture over the chips. Top with 2 cups of the shredded cheese.
Sprinkle the remaining Fritos over the cheese, then add the final 0.5 cup of cheese on top.
Bake for 18–22 minutes, or until the cheese is melted and bubbling.
Remove from the oven and top with shredded lettuce, diced tomatoes, and any additional garnishes before slicing and serving.