01 - Preheat oven to 350°F. Arrange hard taco shells on a baking sheet and warm in the oven for 5–7 minutes.
02 - Heat a large skillet over medium heat. Add ground beef and cook, breaking it up with a spatula, until browned, about 5–6 minutes. Drain excess fat if necessary.
03 - Add the diced onion to the skillet and cook for 2 minutes until softened. Stir in the minced garlic and cook for 30 seconds.
04 - Mix in the tomato paste, chili powder, cumin, smoked paprika, oregano, salt, and pepper. Cook for 1 minute, stirring constantly to coat the meat.
05 - Pour in the beef broth or water. Reduce heat to low and simmer for 5–7 minutes, stirring occasionally, until the liquid has reduced and the mixture is saucy.
06 - Fill each warm taco shell with a generous spoonful of the beef mixture. Top with lettuce, tomatoes, cheddar cheese, and other desired toppings.
07 - Serve immediately with lime wedges on the side.