Spray a 9x13 inch baking dish by non-stick cooking spray. Preheat the oven to 350ºF.
In a large skillet, add the ground beef and chopped onions. Cook over medium heat stirring often until meat is browned and onions have softened. Drain fat, if needed.
Add in water and taco seasoning, stir and simmer for 3-4 minutes.
Add the enchilada sauce and beans to the skillet and stir to fully combine.
Sprinkle about 4 cups of Fritos into the bottom of the prepared baking dish, then sprinkle about 1 cup of cheddar cheese over the Fritos. Spread the meat mixture on top of that for the next layer then top with remaining cheese.
Bake at 350ºF for about 20 minutes until the cheese is melted and bubbly. Once cooked, top with the remaining Fritos.
Allow to cool slightly, then serve with optional topping such as lettuce, tomato, green onions, sour cream, or guacamole. Enjoy!