Put enough water in a frying pan. Add celery stalks, onion, bay leaf spice, carrot and juice of one lemon, as well as a few peppercorns and let it boil. Add salt and reduce the heat.
Add the pike pieces and let them simmer for a short time.
Make a vinaigrette with olive oil, juice of one lemon and pepper, put it in a large enough bowl and mix carefully together with the pike pieces, diced tomatoes, pine nuts and chopped basil. Season again with the juice of a lemon, pepper, salt and olive oil, decorate with basil leaves and serve lukewarm.