1Preheat an oven to 425 degrees F (220 degrees C). Stir together the cornmeal, salt, and baking soda in a bowl; set aside. Place the shortening into a 9 inch cast iron skillet, and place into the oven until the skillet is hot and the shortening has melted.
2Bring some water to a boil in a small saucepan. Add the pork cracklings and boil until tender, 5 to 8 minutes. Once tender, drain, and reserve. Meanwhile, beat the egg in a bowl along with the jalapeno pepper and buttermilk; stir in the cracklings. Stir in the cornmeal mixture until moistened, then pour the batter into the preheated skillet.
3Bake in the preheated oven until the top of the cornbread is brown, and it feels firm to the touch, 30 to 40 minutes. Turn out onto a serving plate and cut into wedges; serve immediately.