Heat 2 tablespoons oil in a nonstick skillet over medium heat; add onion and next 4 ingredients. Sauté 10 minutes or until tender. Remove from heat, and cool.
Stir together cornmeal mix, next 5 ingredients, and 1/4 cup oil until blended. Stir in onion mixture.
Heat remaining 2 tablespoons oil in a 9-inch cast-iron skillet in a 400° oven 10 minutes. Pour cornmeal mixture into skillet.
Bake at 400° for 30 minutes or until done.
