Preheat oven to 450°F (232°C).

Place 1 tablespoon of melted butter and 1 tablespoon of bacon drippings in a 10-inch cast-iron skillet.

Heat the skillet in the oven for 5 minutes.

In a bowl, sift together the cornmeal, flour, salt, pepper, baking powder, and baking soda.

In a separate bowl, whisk together the egg, buttermilk, and milk.

Add the wet ingredients to the dry ingredients and mix just until combined.

Whisk in the remaining 3 tablespoons of melted butter and 2 tablespoons of bacon drippings.

Pour the batter into the hot skillet.

Bake for 20 minutes, or until golden brown and firm.

Cool for 5 minutes before removing from the pan.

Serve warm or cool completely on a wire rack.