Bake fish fillets according to package directions. Set aside, and keep warm.
Cut bread in half crosswise. Split each half lengthwise, and toast.
Stir together mayonnaise and next 6 ingredients. Spread mixture evenly over cut side of bread halves. Place lettuce and fish on bottom bread halves; top with remaining bread halves. Serve immediately.
Note: For testing purposes only, we used Gorton's Southern Fried Country Style Breaded Fish Filets.