Sauté the base: In a large pot, melt 1 tablespoon of butter over medium heat. Once melted, add 1 medium diced onion and cook for 3-4 minutes until soft and translucent. Stir in 2 minced garlic cloves and continue to cook for an additional 1 minute until fragrant.
Add tomatoes: Stir in 1 cup of diced tomatoes and cook for another 3 minutes, allowing the juices to release and mix with the onions and garlic.
Pour in the broth: Add 4 cups of seafood broth to the pot. Bring to a simmer and let it cook for about 10 minutes, allowing the flavors to meld.
Incorporate the seafood: Add 1 pound of shrimp and 1 pound of fresh crab meat to the pot. Sprinkle in 1 teaspoon of Old Bay seasoning. Simmer for an additional 5-7 minutes, or until the shrimp are cooked through and opaque.
Blend for smoothness: Using an immersion blender, blend the mixture until it achieves a smooth consistency. If you don’t have one, you can carefully transfer the soup in batches to a blender.
Finish with cream: Return the blended soup to the pot (if using a regular blender). Stir in 1 cup of heavy cream and cook for another 5 minutes on low heat, ensuring it doesn't boil.
Serve: Taste the bisque and adjust the seasoning if necessary. Ladle into bowls and garnish with chopped fresh parsley before serving.