Melt 2 tablespoons butter in a large skillet over medium-high heat. Add corn, onion, and peppers; sauté 6 to 8 minutes or until tender. Stir in salt and pepper; spoon onto serving dish, and keep warm.
Combine flour, cornmeal, and Creole seasoning in a large shallow dish. Dip fillets in buttermilk, and dredge in flour mixture.
Melt remaining 1 tablespoon butter with oil in skillet over medium-high heat. Cook fillets, in batches, 2 to 3 minutes on each side or until golden. Remove and arrange over vegetables.
Add cream to skillet, stirring to loosen particles from bottom of skillet. Add chopped basil, and cook, stirring often, 1 to 2 minutes or until thickened. Serve sauce with fillets and vegetables. Garnish, if desired.