Step 1: Preheat your oven to 375°F (190°C). In a large skillet, cook 1 pound of ground beef over medium-high heat, breaking it up with a spoon, until browned. Drain any excess fat. Stir in 1 packet of taco seasoning and 1/2 cup of water. Simmer for 5-7 minutes, or until the liquid has mostly absorbed and the mixture is flavorful.
Step 2: Arrange 12 hard taco shells upright in a 9x13 inch baking dish. If they don't stand easily, you can gently lean them against each other or against the sides of the dish. (Pro tip: some like to line the bottom of the dish with a thin layer of refried beans to stabilize shells and add flavor).
Step 3: Evenly distribute about 1/4 cup of shredded cheese into the bottom of each taco shell. This initial layer of cheese acts as a delicious barrier, preventing the shell from getting soggy from the meat filling.
Step 4: Spoon the seasoned ground beef mixture into each taco shell, filling them generously but not overflowing. Aim for an even distribution across all 12 shells.
Step 5: Top the meat mixture in each taco with another generous sprinkle of shredded cheese, about 1/4 cup per taco. This top layer will get beautifully melted and bubbly, creating that signature cheesy crust.
Step 6: Place the baking dish in the preheated oven and bake for 10-15 minutes, or until the cheese is completely melted and bubbly, and the taco shells are golden brown and crispy. Keep an eye on them, as oven temperatures can vary.
Step 7: Carefully remove the baking dish from the oven. Let the tacos cool for a minute or two before serving. This allows the cheese to set slightly and prevents burned tongues. Serve immediately with your favorite toppings like shredded lettuce, diced tomatoes, sour cream, salsa, guacamole, fresh cilantro, or pickled jalapeños. These tacos are best enjoyed fresh!