01 -
Preheat the oven to 400°F (204°C).
02 -
Arrange the hard taco shells standing upright in a 9x13-inch baking dish, leaving space to prevent overcrowding for even crisping.
03 -
Heat olive oil over medium-high heat in a large skillet. Add diced onion, ground beef, salt, and black pepper. Cook for 8–10 minutes, breaking up the beef to ensure even browning until no pink remains. Drain excess grease.
04 -
Stir in tomato sauce and taco seasoning. Simmer for 2–3 minutes until the mixture thickens and absorbs the sauce without drying out.
05 -
Evenly distribute about ⅓ to ½ cup of the meat filling into each taco shell, ensuring an equal portion per shell.
06 -
Sprinkle shredded cheddar-jack cheese evenly over the filled taco shells.
07 -
Bake in the preheated oven for 5–7 minutes until the cheese is melted and the shells are crisp.
08 -
Remove tacos from the oven and optionally sprinkle with chopped fresh cilantro before serving.