Melt the butter in a saucepan, add the onion and garlic. Saute until the onion is transparent.
Add the tomato paste and flour, stirring constantly for 2-3 minutes
Gradually whisk in the chicken stock, whisking out any lumps. Add the thyme and paprika, season with salt and pepper
Bring the mixture to simmer and then add the seafood. You can additional items, like whole shrimp, if you desire. Cook for 5-7 minutes until the seafood is cooked through.
Remove any whole seafood and use an immersion blender to puree the soup until it is smooth.
Add heavy cream and brandy/sherry if using.
Return whole seafood and cook the soup for another 1-2 minutes.
Garnish and serve.