Preheat oven to 400°F. Rinse the fillets and pat dry paper towels.

Combine crab meat, green peppers, mustard powder, Worcestershire
sauce, salt, white pepper and crushed saltines. Combine the egg
white and 1 tbsp. mayonnaise. Stir this into the crab meat mixture.

Brush the flounder fillets with melted butter. Place in a lightly greased,
shallow baking dish. Spoon the crab mixture over the fillets and
drizzle with any remaining butter.

While the fish is baking, lightly beat the egg yolk in a small bowl.
Stir in 5 tbsps. of mayonnaise. Remove fish from oven and spread
this mixture over the stuffing. Sprinkle with paprika and parsley.

Increase oven temperature to 450°F and bake until golden and
bubbly, about 6 minutes.