Preheat oil to 350˚F.
For hard shell tacos: Create a small aluminum foil cylinder about 1 inch thick and place it in the center of one of the cooked tortillas Place the tortilla in the oil. with the foil cylinder and gently fold half of the tortilla over the other side, and hold down together with a pair of heat resistant tongs.
Hold and fry for 2 to 3 minutes or until the tortilla has fried enough to kept its folded shape.
Flip the shell and continue to fry for 3 to 4 minutes or until the shell turns golden brown and is fully crisp. Drain onto a paper towel and season with salt and pepper. Transfer to a cooling rack lined with a baking sheet.
Repeat until all hard shells have been made. Use immediately or store in an airtight container for 3 to 4 days.
Puffy Shells: Carefully place 1 raw corn tortilla into the oil and fry for 2 to 3 minutes. Flip and continue to fry for an additional 2 to 3 minutes or until shells have puffed up, are golden brown, crisp, yet still slightly pliable. Drain onto a paper towel and season with salt and pepper.
Repeat until all puffy shells have been made. Use immediately. (Puffy taco shells generally do not hold very well and should freshly fried and consumed immediately).