Rinse fish thoroughly in cold water; pat dry, and set aside.
Cream butter in a small mixing bowl; stir in egg, parsley, pimiento, 1/4 teaspoon salt, and pepper. Set aside.
Combine flour and remaining salt in a large mixing bowl; stir well. Dredge fish in flour mixture. Place fish on well-greased rack in a broiler pan; brush with oil. Broil fish 3 inches from heating element 8 minutes or until fish flakes easily when tested with a fork.
Transfer fish to a warm serving platter; spread each with reserved butter mixture. Garnish with lime slices; serve immediately.