1: Prepare 200 g tomato and, after cutting into small pieces, salt and leave to wait in a sieve to draw out some of the juice.
2: Boil 400 g potatoes, peel and cut in half lengthways, then into small pieces.
3: Slice 4 hard-boiled eggs when cooled. Cut 100 g cervelas into small dices.
4: Slice 30 g gherkins in vinegar.
5: Roughly chop the parsley.
6: Put all the ingredients into a salad bowl.
7: Add 200 g mayonnaise and mix well. Leave for at least an hour before serving to allow the potatoes to absorb some of the creaminess of the mayonnaise.