Wash potatoes thoroughly and cook in boiling water for about 20 minutes. Drain, rinse with cold water and peel. Let potatoes cool down and cut into slices. Wash, clean and cut the tomatoes into eighths.
Peel and chop the onions. Wash the herbs and dab dry. Cut chives into fine rolls, chop parsley finely. Mix vinegar with salt and pepper and add oil. Add herbs and diced onions.
Mix the potatoes, tomatoes and onion vinaigrette and leave to stand for about 30 minutes.