The dish with its sauce resembles the well-known carbonara pasta, only with zucchini and mackerel.
Cook pasta according to instructions until al dente. Save some water from cooking.
If the zucchini is not young, then peel and remove the loose core with seeds. Cut the pulp into cubes. Finely chop the onion.
Heat a little oil in a large frying pan, fry the onion, add the zucchini. Season, add rosemary leaves.
Cut the fish into pieces, add to the pan.
For sauce, beat eggs with milk, add grated parmesan.
Transfer the spaghetti to the pan, add the sauce and water from cooking pasta. Cook a little more while stirring.
Sprinkle the finished dish with lemon zest. Enjoy your meal!