Preheat oven to 400F. If using a cast iron skillet, put 1 tbsp butter in a 9in skillet and place in oven while it preheats.
If not using cast iron, grease an 8in square pan (do not preheat in oven).
Place all ingredients in a large bowl, stir until just combined. Batter will be slightly lumpy.
Pour mixture into greased skillet/pan, and bake for 20-25 minutes until a toothpick inserted into the center comes out clean.
Cool slightly, and serve.
Recipe Notes
**Cardinal Rule** Add cooked bacon or diced Spanish chorizo for an even bigger flavor boost.