01 - Heat a large skillet over medium-high heat. Add the ground beef, breaking it apart with a spoon, and cook until browned, about 4 to 5 minutes.
02 - Add the finely chopped onion and cook for 2 to 3 minutes until softened. Stir in the minced garlic and cook for an additional 30 seconds.
03 - Sprinkle in chili powder, ground cumin, smoked paprika, salt, and black pepper. Stir thoroughly to evenly coat the beef and onion mixture.
04 - Pour in the tomato sauce and water. Stir well, reduce heat to low, and simmer the mixture for 5 minutes until slightly thickened.
05 - Heat taco shells according to package instructions until warm and pliable.
06 - Fill each taco shell with the beef mixture, then top with shredded lettuce, diced tomato, shredded cheddar cheese, and optional sour cream and cilantro.
07 - Serve tacos immediately for best freshness and flavor.