If fish fillets are large, cut into serving pieces.
Mix butter and lemon juice.
In another bowl, mix flour, salt and white pepper.
Dip fish into butter mixture; coat fish with flour mixture.
Place fish in ungreased square baking dish, 8x8x2 inches.
Pour remaining butter mixture over fish; sprinkle with paprika.
Cook uncovered in 350 degree oven until fish flakes easily with fork, 25-30 minutes. Garnish with parsley sprigs and lemon slices if desired.