In a large skillet over medium heat, melt the butter and olive oil. Sauté the onion and garlic until softened, about 3-4 minutes. Then, add the diced carrots, celery, and mushrooms, cooking for an additional 5-6 minutes until tender.

Sprinkle flour over the sautéed vegetables, stirring constantly for about 1-2 minutes to create a roux. Gradually whisk in seafood broth and heavy cream, bringing it to a simmer. Season with paprika, Old Bay seasoning, salt, and pepper to taste. Allow the sauce to thicken for about 5 minutes.

Gently fold in shrimp, crab meat, and frozen peas. Cook over low heat until the shrimp turns pink, about 3-4 minutes. Stir in chopped parsley and set aside to cool slightly.

In a mixing bowl, combine all-purpose flour, baking powder, garlic powder, and salt. Mix in shredded cheddar cheese. Pour in melted butter and buttermilk, mixing gently until just combined.

Preheat your oven to 375°F (190°C). Grease a baking dish and pour the seafood filling into the bottom. Dollop the biscuit dough over it, leaving spaces for steam to escape.

Bake the assembled pot pie in the oven for 25-30 minutes or until biscuits are golden brown. Cover loosely with foil if they brown too quickly.

Remove from the oven and let cool for 5 minutes. Garnish with parsley or extra cheese before serving.