Shrimp and Mussels with Sofrito

In a large pot over medium, stir together sofrito and mussels. Add wine and 1/2 cup water and bring to a boil. Stir in shrimp, cover, and cook until mussels open and shrimp are opaque throughout, 6 minutes, stirring once. (Discard any unopened mussels.) Remove from heat and stir in butter until melted. Season with salt and pepper and serve with bread.