Preheat your oven to 375°F (190°C) to ensure it reaches the perfect temperature for baking.

Heat a tablespoon of olive oil in a large skillet over medium heat. Add the diced onion and minced garlic, sautéing until the onions turn translucent, about 2-3 minutes.

Add the ground beef (or your chosen substitute) to the skillet, breaking it apart as it cooks. Mix in the taco seasoning, tomato sauce, salt, and pepper. Simmer for about 5 minutes.

Warm your taco shells in the oven for about 2 minutes to make them pliable. Fill each shell with the meat mixture and top with shredded cheese.

Place the filled taco shells upright in a greased baking dish. Bake for 10-15 minutes, or until the cheese is melted and bubbly.

Remove the tacos from the oven and let them cool slightly. Garnish with fresh toppings like lettuce, tomatoes, onions, and cilantro.