Heat a large skillet over medium heat.
Add the ground beef and cook, breaking it apart with a spoon, until browned (about 5–7 minutes).
Drain excess grease if needed.
Stir in the diced onion and cook for 2–3 minutes until softened.
Add the minced garlic and cook for another minute.
Stir in the tomato paste, chili powder, cumin, paprika, oregano, salt, and black pepper.
Add the water or beef broth and mix well.
Reduce the heat and let the meat simmer for 5 minutes, stirring occasionally, until the sauce thickens.
Warm the taco shells according to the package instructions.
Fill each shell with the seasoned beef and your favorite toppings.
Serve immediately with your choice of sides.