Preheat & Prep: Heat oven to 450°F. Place 1 tablespoon of shortening in an 8-inch ovenproof cast-iron skillet and place it in the oven to heat for 5 minutes.
Mix Batter: In a medium bowl, whisk the egg. Stir in the buttermilk, oil, and cornmeal mix until smooth. The batter should be creamy and pourable.
Bake: Carefully tilt the hot skillet to coat the bottom with hot shortening. Pour the batter into the skillet.
Cook: Bake for 20 to 25 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.