Preheat the oven to 375 degrees F (190 degrees C). Set a large stock pot or Dutch oven over medium-high. Add sausage and cook, stirring occasionally, until browned, about 3 minutes. Remove sausage using a slotted spoon. Do not wipe pot clean.
Add red and green bell peppers, onion, celery, and butter. Cook, stirring occasionally, until softened, about 3 minutes. Season with Old Bay seasoning, bouillon, garlic powder, gumbo file, salt, and pepper. Cook, stirring, until fragrant, about 30 seconds. Stir in tomato paste until mixture is well coated. Add flour and cook, stirring occasionally, until fragrant and nutty smelling, 1 to 2 minutes.
Stir in canned tomatoes and chicken broth, and increase heat to high. Bring mixture to a boil, reduce heat, and simmer undisturbed until filling has thickened, 15 to 20 minutes.
Return sausage to pot with shrimp, and crabmeat. Cook, stirring occasionally, until shrimp is bright pink and cooked through, about 6 minutes. Season with hot sauce or cayenne to taste, if desired. Remove from heat and allow to cool until ready to use.
Roll out puff pastry on a lightly floured surface to 1/4-inch thickness. Cut out two 6-inch wide round circles. Repeat with second puff pastry sheet. Whisk together egg yolk and 1 tablespoon of water in a small bowl until smooth.
Fill 4 (16-ounce) ramekins with 2 cups of creole pot pie filling. Top each with puff pastry circles and brush all over with egg wash. Cut 3 to 4 venting slits in the middle of each pastry circle and set ramekins on a large-rimmed baking sheet.
Bake in the preheated oven until puff pastry is golden brown, about 20 minutes. Remove from oven and allow pies to cool for 15 minutes before serving.
