Season diced chicken liberally. Heat 2 tablespoons oil in large skillet over medium-high heat. Add the chicken and cook for a couple of minutes. Dump in the diced green chilies. Stir and cook until chicken is totally done inside. Turn off heat and set aside.
Get all other ingredients (grated cheese, sliced lettuce, diced tomato, sour cream, and hot sauce) ready.
Also have a plate ready, as well as a stack of five or six paper towels to hold in your hand (this is for frying the tortillas)
To fry the tacos, heat a couple of inches of canola oil in a heavy skillet over medium-high. Place some chicken in the middle of a tortilla, then fold tortilla in half. Clamp the tortilla shut with a pair of heat-proof metal tongs, then carefully lay the taco—one side down—in the oil. As you lay it in the oil, use the tongs to hold the top side down for a few seconds to form it in place. Once it stays put, repeat with two other tacos. Turn tacos after 30 to 45 seconds, or when each side gets light golden brown (not too brown.)
One at a time, remove tacos from the pan with tongs, holding sideways as you remove them to allow oil to drip out of the sides. Place the taco in the stack of paper towels. Fold the sides and corners around the taco to tightly hold it, then give it three or four shakes to remove excess oil. Remove it from the paper towels and place on a plate. Repeat with other tacos in the pan.
As you continue frying the other tacos, have someone carefully place some grated cheese inside the tops of the tacos (gently pry them open just enough to place the cheese in). Then just let them sit until ready to serve—the cheese will melt as it sits in the warm taco.
To serve, garnish in this order: a smear of sour cream, dashes of hot sauce, shredded lettuce, diced tomato. You’ll need to slightly open up the tops of the tacos to get all the garnishes in there.
Tacos will be hot for a minute or two after frying, so let them cool slightly so you don't burn your hands :)