1In 12-inch nonstick skillet, cook bacon over medium-high heat 5 to 8 minutes, stirring occasionally, until browned. Remove bacon from skillet with slotted spoon; set aside.
2Reduce heat to medium. Add onion to bacon fat; cook 5 minutes, stirring occasionally. Meanwhile, in shallow dish, mix Bisquick mix and cornmeal. In another shallow dish, beat egg. Dip fish into egg, then coat with Bisquick mixture.
3Remove onion from skillet with slotted spoon; set aside. Place fish in skillet with bacon fat. Cook over medium heat 3 to 5 minutes, turning once, until lightly browned.
4Add tomatoes to skillet. Reduce heat; simmer about 5 minutes or until fish flakes easily with fork. Top fish with bacon and onion before serving.