Cut the ends of the green beans, thin them out, wash them and break them into halves or thirds. Then cook them for 8 to 10 minutes in steam or 15 minutes in boiling salted water, keeping them "al dente".
Drain the herring fillets, split them in half lengthwise and cut them into bevelled sections.
Peel and slice the onion into rings then separate the rings. Cut the tomatoes into small wedges.
When the green beans are cooked, drain them and season them hot with oil and vinegar. Arrange them on the plates, then garnish with the pieces of herring and the tomato wedges.
Do not add salt because of the pickled herring fillets, but season generously with pink peppercorns and white peppercorns. Sprinkle with chopped parsley and finely chopped chives.
You can serve this spring salad still warm or chilled.
