Quickly wash the potatoes and transfer them to the cooking pot. Cover all the potatoes with some cold water and a pinch of salt.
Bring this to a boil and cook the potatoes for about 10 minutes.
Almost ready!
Wash the other vegetables and the apple. Cut the little gems into quarters, the apple in slices and some tomatoes in half. To keep the apple slices pretty, you can dress them with some lemon juice!
Place the mackerel in the middle of the serving board and remove some skin. Put all vegetables/fruits next to it.
Once the potatoes are lukewarm, or completely cooled down, you can add those as well to the salad.
Chop 1 or 2 stalks of spring onions and add those as topping.