Top with onion lemon slices and bay leaf sprinkle with 14 teaspoon salt
Bring to a boil
Cover reduce heat and simmer for 8 minutes or until fish flakes easily when tested with a fork
Combine milk and flour in a saucepan stirring well
Add mustard dill seed lemon rind 14 teaspoon salt and pepper Cook over medium heat stirring constantly until thickened Gradually stir about 14 of hot milk mixture into egg yolk add to remaining hot milk mixture stirring constantly