In a large skillet, heat the olive oil over medium heat.
Add the diced onion and sauté for 2-3 minutes until soft and translucent.
Stir in the minced garlic and cook for an additional 30 seconds until fragrant.
Add the ground beef to the skillet and cook, breaking it apart with a spoon, until it is browned and no longer pink, about 5-7 minutes.
Drain any excess fat from the beef.
Stir in the chili powder, cumin, paprika, salt, and pepper. Cook for another 1-2 minutes, ensuring the beef is well coated with the spices.
While the beef is finishing up, warm the taco shells or tortillas according to package instructions.
Assemble the tacos by filling each shell with the seasoned meat, and topping with lettuce, tomatoes, cheese, sour cream, and cilantro as desired.
Serve immediately and enjoy!