Drain sardines and pat dry. Flake them in a mixing bowl with a fork.
Cream the softened butter in a separate bowl until smooth and fluffy.
Fold the sardines into the butter. Stir in crème fraîche, Dijon, lemon juice, and zest.
Mix in shallot, capers, cornichons, parsley, and chives. Season with salt, pepper, and paprika.
Adjust texture with a splash of olive oil if thick. Taste and tweak seasoning.
Chill 30 minutes for flavors to meld. Serve with toasted baguette or crackers.