To fry unfilled taco shells, immerse in hot oil, turn over immediately, and fold in half. Fry, turning as needed, until slightly crisp but still flexible on both sides, 40 to 50 seconds total. Drain on paper towels.
For soft tacos, instead of frying the tortillas, wrap each dozen in plastic wrap and cook one packet at a time in a microwave oven on full power (100%) until hot and steamy, about 45 seconds. Serve tortillas with chicken and condiments.
Prep and cook time: 1 3/4 hours
1. Put lettuce, cheese, tomatoes, salsa, sour cream, guacamole, and cilantro in separate bowls (see notes); cover and chill.
2. Line two shallow baking dishes (9 by 13 in. or larger) with several layers of paper towels and set in a 200° oven. Also line a 10- by 15-inch baking pan with paper towels; set beside range.
3. Pour about 1/2 inch oil into a 10-inch frying pan over medium-high heat. When oil reaches 350° on a thermometer, dip one tortilla in and, with tongs, quickly turn it over; immediately spoon about 3 tablespoons chicken in a mound in the center. At once, using the tongs and a small spatula, fold tortilla in half and hold down gently until bottom side is crisp but still slightly flexible, 15 to 20 seconds; turn over and fry other side the same way. Lift taco from oil and tilt one end down to drain off excess oil. Set briefly in towel-lined baking pan to drain, then transfer to a baking dish in the oven. Repeat to fry remaining tacos, adding more oil as needed.
4. Set out tacos with bowls of condiments and hot sauce for guests to fill as desired.