1. Peel the potatoes, rinse them, and cut them into cubes. Place them in a saucepan and cover them with tap water. Put them on the heat and bring the water to a boil. Lower the heat to medium and boil for 10-15 minutes, or until the potatoes are tender.
Coarsely grate the zucchini and squeeze out the excess moisture well. Finely chop the spring onions.
2. Drain the potatoes and place them in a bowl. Mash them while they are hot with a fork or a potato masher. Add all the remaining ingredients and mix well.
3. Take 100g of the mixture and shape it into a patty (bifteki). Place it on a baking sheet lined with parchment paper. Repeat with the remaining ingredients. If you wish, coat the patties in breadcrumbs.
Bake in a preheated oven at 180°C (350°F) for 20-25 minutes, or until golden brown.
For the Aioli Sauce: In a bowl, mix all the sauce ingredients together. Serve the tuna patties with the Aioli sauce.