Sauté shrimp shells in a large pot with butter for 5 minutes.
Add chopped onions and garlic. Cook until softened.
Stir in the tomato paste and paprika. Mix well.
Pour in the seafood stock and simmer for 20 minutes.
Remove the shells from the pot. If available, use a strainer.
Add the shrimp to the pot. Cook until they turn pink.
Blend the soup until smooth with an immersion blender.
Remove the pot from the heat and stir in the heavy cream.
Season with salt and pepper to taste.
Serve hot with crusty bread for dipping.