In a large pot, heat the olive oil and butter over medium heat. Add the chopped onion, garlic, carrot, and celery. Sauté for about 5-7 minutes, until the vegetables are softened and the onion is translucent.

Stir in the tomato paste, paprika, and cayenne pepper. Cook for an additional 2 minutes, stirring frequently.

Pour in the seafood stock and bring the mixture to a simmer. Allow it to cook for about 15 minutes to let the flavors meld.

Use an immersion blender to puree the soup until smooth. If you don’t have an immersion blender, carefully transfer the soup in batches to a regular blender and blend until smooth.

Return the pureed soup to the pot and stir in the heavy cream. Add the cooked langostino tails and heat through for about 5 minutes. Season with salt and pepper to taste.

Serve hot, garnished with fresh parsley.