Place bread in a food processor; pulse 10 times or until coarse crumbs measure 1 1/4 cups. Arrange breadcrumbs on a baking sheet.
Bake at 425 for 5 minutes or until light golden. Cool; place in a shallow dish.
Cut fish into 16 (3 x 1-inch) pieces; pat dry with paper towels.
Sprinkle fish evenly with 1/4 teaspoon salt and 1/4 teaspoon pepper.
Place flour and egg in separate shallow dishes. Dredge 1 fish finger in flour, shaking off any excess. Dip fish in egg; dredge in breadcrumbs. Repeat procedure with remaining fish, flour, egg, and breadcrumbs. Arrange coated fish on a wire rack on a baking sheet; lightly coat fish with cooking spray.
Bake at 425 for 8 minutes or until desired degree of doneness.
Bring chicken broth to a simmer in a saucepan over medium heat. Stir in peas; cover and cook 2 minutes.
Remove from heat; stir in butter, mint, remaining 1/4 teaspoon salt, and remaining 1/4 teaspoon pepper.
Place pea mixture in a food processor; process until smooth.
Place about 1/3 cup pea puree in the middle of each of 4 plates. Stack 4 fish fingers on the puree.