Preheat oven to 375 F. In a medium saucepan, brown meat over medium-high heat. In a separate bowl, combine cornmeal, corn, salt, baking soda, milk, and egg. Blend well. Pour half of cornmeal mixture into cast iron skillet. Layer ground meat, onions, cheese, and jalapenos, on top of corn batter in skillet. Pour remaining cornmeal over layers. Place in oven and bake 45 minutes or until golden brown.