Microwave the cod for 1 minute. Let it cool down and then flake with your hands onto a plate.
Crush the black olives with the extra-virgin olive oil and use the mixture to marinate the cod. Chop the tomatoes into quarters and deseed. Put the seeds by for later. Cut the tomato flesh into small cubes and sprinkle over the cod and rocket.
Scatter the pine nuts on top, together with a few finely sliced onion rings. Top off with the tomato seeds in the style of caviar.