1. Cut the potatoes in small pieces (3-4 cm) to speed up the boiling process. Bring the potato pieces to a boil in a salted water pan. When the water is boiling, add the eggs and let everything boil for 12 minutes.
2. In the meantime, half the cucumber lengthwise and thinly slice crosswise. Peel the carrot and quarter lengthwise, then thinly slice crosswise. Add 1 tsp of salt and let them release their juices in a bowl.
3. After 10-12 minutes remove the eggs and check if the potatoes are soft, otherwise leave them a few more minutes until the reach the desired consistency.
4. While the potato finishes cooking, run the boiled eggs under cold tap water. Peel the eggs, save one of the egg yolks and finely chop the rest. Then add it to a medium bowl. When the potato is cooked, transfer to the bowl with the egg and mash with a fork until uniform.
5. Add the ¼ cup of mayonnaise, 1 tsp dijon mustard, 1 tbsp of sugar and vinegar to the mashed potato mixture and stir to coat. Season to taste with salt and white pepper (also add ¼ tsp msg if using). Discard the liquid from the salted cucumber and carrot with your hands, and fold them into the potato and egg mixture. Taste and adjust seasonings where necessary.
6. If making a sandwich, toast lightly the bread with some olive oil. Add fresh salad leaves and spread a good amount of potato salad on top. Garnish with tuna, grate some egg yolk and lightly frizzle some sesame oil on top.

Other possible toppings to add here: (red) onion 🧅, corn 🌽, peas, apples, raisings or (wal)nuts.