01 - Preheat oven to 350°F. Place 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 up with a spoon, until browned, about 5–6 minutes. Drain excess fat if necessary.
03 - Add onion and garlic to the skillet with the beef. 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 - Add tomato sauce and water, stirring to combine. Simmer for 3–4 minutes until slightly thickened. Remove from heat.
06 - Fill each warm taco shell with a generous spoonful of seasoned beef mixture. Top immediately with shredded cheddar cheese so it melts slightly.
07 - Layer shredded lettuce, diced tomatoes, and any optional toppings such as sour cream, black olives, green onions, or cilantro.
08 - Serve tacos right away while shells are crispy, accompanied by salsa for dipping or drizzling.