In a large, heavy pot over medium heat, melt butter. Add onion and celery, cooking until softened, about 5 minutes. Season with salt, pepper, and Old Bay seasoning.

Stir in minced garlic and tomato paste, cooking until the garlic is aromatic and the vegetables are well-coated, about 2 minutes.

Sprinkle flour over the vegetables, cooking until the flour is fully absorbed, about 1 minute.

Gradually pour in fish stock and white wine, adding the bay leaf. Reduce heat and simmer, allowing the liquid to reduce and flavors to blend, about 30 minutes, stirring occasionally.

Remove the bay leaf and use an immersion blender to purée the soup until smooth.

Return the pot to a medium-low heat and stir in heavy cream and half of the crab meat. Heat until just warmed through, about 5 minutes.

Serve the bisque in bowls, garnished with remaining crab meat and chopped parsley.