Preheat your oven to 400°F (200°C).

Melt 4 tablespoons of unsalted butter in a large skillet over medium heat. Add minced garlic, chopped onion, and diced celery, and sauté for 5 minutes until the vegetables are soft.

Sprinkle in 0.25 cup of all-purpose flour, stirring constantly for about 1 minute. Gradually whisk in 1 cup of seafood stock and 1 cup of heavy cream, cooking for 5 to 7 minutes until thickened.

Stir in 1 tablespoon of Old Bay seasoning, salt, and black pepper. Fold in 1 pound of raw shrimp and 1 cup of cooked lobster meat, cooking until the shrimp turn pink, about 2 to 3 minutes. Mix in chopped parsley.

In a bowl, combine 2 cups of all-purpose flour, 1 tablespoon of baking powder, 1 teaspoon of garlic powder, and a pinch of salt. Cut in 0.5 cup of unsalted butter until resembling coarse crumbs. Add 1 cup of shredded cheddar cheese and 0.75 cup of whole milk, mixing until just combined.

Transfer the seafood filling into a baking dish and spoon the biscuit dough over the filling, leaving some filling visible.

Bake the pot pie in the oven for 20 to 25 minutes until the biscuits are golden brown and the filling is bubbling.

Let the pot pie rest for 5 to 10 minutes before serving.