In a medium saucepan, combine the reserved shrimp shells and seafood stock. Bring to a boil, then reduce heat and simmer for 20 minutes. Strain the stock through a fine-mesh sieve, discarding the shells, and keep the liquid warm.

In a large Dutch oven or heavy-bottomed pot, melt the butter over medium heat. Add the onion, celery, and bell pepper. Sauté for 6-8 minutes until the vegetables are soft and translucent.

Add the minced garlic and cook for an additional 1 minute until fragrant.

Sprinkle the flour over the sautéed vegetables and stir constantly for 3-5 minutes to create a blond roux. The mixture should be aromatic and slightly golden but not brown.

Slowly whisk in the warm shrimp stock, adding about 1 cup at a time and stirring constantly to ensure a smooth, lump-free base.

Stir in the whole kernel corn, cream-style corn, Creole seasoning, cayenne pepper, and thyme. Bring the mixture to a gentle boil.

Reduce the heat to low and simmer, uncovered, for 20 minutes, stirring occasionally to prevent the bottom from scorching.

Stir in the heavy cream and return the bisque to a gentle simmer.

Add the raw shrimp to the pot. Cook for 3-5 minutes, or just until the shrimp turn pink and opaque. Do not overcook.

Fold in the green onions and parsley. Season with salt and white pepper to taste. Serve hot with crusty French bread.