01 - Preheat oven to 350°F. Arrange hard taco shells on a baking sheet and warm for 5 minutes until crispy.
02 - Heat a large skillet over medium heat. Add ground beef and cook, breaking apart with a spoon, until browned, approximately 5–6 minutes. Drain excess fat if needed.
03 - Add chopped onion and minced garlic to the skillet. Cook for 2–3 minutes until softened and fragrant.
04 - Stir in chili powder, cumin, smoked paprika, oregano, salt, and black pepper. Cook for 1 minute to bloom the spices.
05 - Pour in tomato sauce and water, stirring to combine. Simmer for 3–4 minutes until the mixture thickens slightly. Remove from heat.
06 - Fill each warmed shell with a generous portion of seasoned beef. Top with shredded cheddar cheese, lettuce, diced tomatoes, and any desired optional toppings.
07 - Serve immediately with salsa and optional sour cream on the side.