Remove skin and bones from fish. In a medium bowl, mix fish with onion and hot pepper sause with a fork, breakind fish into small pieces. Mix in mayonnaise. Season to taste with salt and pepper. Cover, and refrigerate for 2 hours.
Whole flounder-cleaned-eheat oven to 350 degrees. Lightly grease a large casserole dish or a baking sheet lined with tin foil.
Heat butter over medium-low heat in a large saucepan. Stir in onion, green onions, bell pepper,celery and garlic. Cook slowly, stirring occasionally until onions are soft.
Remove pan from heat and stir in shredded crabmeat, seasoning, bread crumbs, salt and pepper.
Melt butter in sausepan over low-medium heat. add lemon juice, garlic, wine, hot sauce, and seasoning. Slowly simmer for about 2 minutes. Add the cream and simmer until will mixed. Gently stir in the crabmeat being careful not to break it up. Simmer until the crabmeat is heated through. Spoon over fish fillets and garnish with chopped green onions.Heat grill to medium-high. Place the fish fillets flesh side down on tray. Liberally brush the scales with oil to keep from sticking to the grill.