In a large saucepan or Dutch oven, melt the butter over medium heat. Add the onion and garlic and cook until the onion is translucent, about 5 minutes.

Add the tomato paste and flour and cook, stirring constantly, for 2-3 minutes.

Gradually whisk in the seafood or chicken stock, making sure to whisk out any lumps. Add the thyme and paprika, and season with salt and pepper.

Bring the mixture to a simmer and add the seafood. Cook for 5-7 minutes, until the seafood is cooked through.

Using a slotted spoon, remove the seafood from the pot and set it aside. Using an immersion blender or regular blender, puree the soup until smooth.

Return the soup to the pot and add the heavy cream. If using, add the brandy or sherry. Heat through, but do not boil.

Return the seafood to the pot and cook for 1-2 minutes, until heated through.

Serve hot, garnished with chopped fresh parsley.