Make the filling. Heat the oil in a medium skillet over medium-high heat. Add the ground beef and cook for 6 to 8 minutes, breaking up the meat into small pieces as it cooks. Drain and discard any excess grease if necessary.

Add the tomato paste, water, chili powder, ground cumin, salt, garlic powder, onion powder, and dried oregano. Stir together until fully combined. Cook for 1 more minute.

Remove the skillet from the heat and stir in the lime juice.

Make the crunchy taco shells. Line a large baking sheet with paper towels. Heat 1 inch of frying oil in a sauté pan or pot over medium-high heat until hot. (If the oil sizzles when you dip the edge of the tortilla in, it’s ready.) Working 1 tortilla at a time, add in a tortilla and fry for 15 seconds. Flip it over and use tongs to fold the tortilla in half to create a “U” shape. Fry for 15 seconds like this, then flip once more, continuing to fold the tortilla with the tongs, and fry on the other side for 15 more seconds. Transfer to the prepared baking sheet to drain off any excess oil. Continue frying the remaining tortillas.

Serve the ground beef in the taco shells topped with shredded lettuce, cheese, tomatoes, and sour cream.