1. Preheat the oven to 425°.
2. 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.
3. 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.
4. 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. Serve with lemon wedges, if desired.