Chop the tomatoes, olives and capers. In a large pan, fry in oil (over low heat), the onion cut into julienne strips and when it begins to brown and add the chopped cod. Then cover and turn off the fire. Apart, cook the stuffed “gnocchi” (dumplings) in salted water. Cook for one minute, no more. Then drain and put the dumplings into the pan with the cod by adding the tomatoes, capers, olives and a drizzle of olive oil. Cook until creamy.
Serve and garnish with fresh basil leaves.