Combine the flour, cornmeal, starter, and water or milk in a bowl, mixing to moisten everything. Cover let rest in a warm place for 8-24 hours.
When ready to bake, preheat oven to 350°F. Place a 10 or 12-inch cast-iron skillet in the oven with 2 Tbsp. bacon grease or coconut oil.
In a small bowl, whisk eggs and mix in honey and melted butter.
Pour wet ingredients into the soaked flour and fold in just a couple of times. Sprinkle salt, baking soda, and baking powder over the wet mixture. and fold over several times until thoroughly combined.
Carefully remove the hot skillet from the oven, gently swirl the melted fat around to evenly coat the skillet, then pour the batter into the hot skillet.
Place skillet in oven and bake for 30-40 minutes or until a knife inserted into the center comes out clean.
Cool at least 10 minutes before cutting.