Total time 25 min
Boil the potatoes: time will vary according to quantity (between 10 and 30 minutes). Test with a knife to make sure they are well cooked. You can speed up the process by cutting the potatoes beforehand.
Boil eggs for 8-10 minutes.
For the mayonnaise: - Break an egg into a blender, add a splash of vinegar, some salt and plenty of olive oil. - Put the blender arm at the bottom of the mixture and blend, leaving it there until the mixture emulsifies. - When it starts to emulsify, move the blender gently up and down. - Set aside the mayonnaise in the fridge until it’s time to serve.
Wash the tomatoes in plenty of water, if necessary add a little vinegar or lemon juice and leave to soak to make sure they are thoroughly cleaned.
Peel the onions, chop and mix in with tomatoes, potato and sliced eggs.
Finally, add the flaked tuna and mayonnaise. Now mix it all together.