Hard boil the eggs, rinse in cold water for a long time and let cool for at least 10 minutes. Then cut the eggs very small, into small cubes. Also chop the onion very finely, chop the herbs. Mix the mayonnaise with the crushed eggs, add the herbs. Season everything well with salt and pepper. If possible, let it steep for an hour in the refrigerator, then spread between two slices of white bread and divide diagonally. Sufficient for about 4 people.