Preheat your oven to 400°F (200°C).

In a large skillet over medium heat, cook the ground beef and onion until browned and translucent.

Stir in the minced garlic and taco seasoning. Cook for another minute.

Add the tomato sauce or salsa and simmer for 5 minutes.

Fill each hard taco shell with the beef mixture and sprinkle with shredded cheese.

Bake in your preheated oven for 10-15 minutes until the cheese is bubbly and the shells are golden brown.

Let cool for a minute, then add fresh toppings before serving.