Preheat your oven to 400°F (200°C).

In a large skillet, heat olive oil over medium heat. Add onions, bell peppers, and celery. Sauté until the vegetables become tender, about 5 minutes.

Stir in the minced garlic and cook for another minute until fragrant.

Add shrimp, crab meat, and fish chunks to the skillet. Stir gently to combine.

Pour in the heavy cream and seafood stock. Add Cajun seasoning, and season with salt and pepper. Stir to combine and allow simmering for about 10 minutes, until seafood is cooked through and sauce thickens slightly.

Roll out the pie crust in a pie dish, trimming off any excess dough.

Carefully pour the seafood mixture into the crust, ensuring it's evenly distributed.

Cover with the top layer of pie crust, pressing the edges to seal. Cut slits in the top crust to allow steam to escape.

Place the pie in the preheated oven and bake for 30-35 minutes or until the crust is golden brown.

Once baked, let it cool slightly before slicing. Garnish with fresh parsley before serving.