Recipe: Venetian Baccala

Here's some info about baccala (salt-cured cod) and stoccafisso (air-dried cod, or stockfish). I suspect the dish you ate used stockfish instead of salt cod. The following information came from La Cucina di Lidia by Lidia Bastianich, a really great Italian cook.
Before refrigeration, the two most efficient means of preservation produced what the Italians term baccala and stoccafisso; respectively, salt-cured and air-dried cod. Today, these two products are no longer mere substitutes for fresh cod, but are esteemed as delicacies in their own right, preferable for some uses to freshly caught fish.
Baccala, the less costly of the two is boneless and relatively moist, but too salty for immediate use and must be soaked overnight or longer in several changes of water. Stoccafisso (from the English "stockfish") is drier, with a woody texture and appearance and usually is given a light pounding, to break down its fibrous texture, before being soaked in the same manner as baccala. It is then boiled, cleaned from the bone, and typically, beaten to a mousselike consistency with oil or cream.
In Istria, where Lidia grew up, they used stoccafisso for a dish that sounds like what you described. It is called Baccala Mantecato (whipped stockfish). No matter that the dish is called Bacala mantecato, it actually was made with stockfish.
Here is the recipe:
Ingredients: 1 whole dried cod (stockfish) about 1-1/2 pounds
3 cloves garlic, chopped fine
2 cups olive oil
1/4 cup fish stock
salt and pepper to taste

Lightly beat the surface of the stockfish with a wooden mallet. Soak it overnight in several changes of cold water. Cut the fish into four parts and poach it in 6 quarts of water until the fish begins to fall from the bones, about 1-1/2 hours. Drain and cool, then remove and discard the bones, but not the skin and cartilage.
Place the fish and garlic in a food processor and, with the motor running, gradually add the oil and stock in thin streams and alternating batches. With the motor turned off, taste the mixture and add salt and pepper to taste. Restart the processor and let it run until the mixture is light in color ant texture, like a mousse.
Serve as a spread for toast, crackers, or plain Italian bread.
Serves 6-8