Put the peeled onions in a bowl, pour boiled salted water over them and let them steep for at least 12 hours.
Then pour off the water and collect it.
Bring the vinegar, wine, sugar and all other spices (except for the saffron) to the boil, add the onions and cook for approx. 5 minutes, season with the onion water, bring to the boil again.
Pour the onions into the prepared jars, add the saffron to the stock and then pour the stock over the onions and close the jars immediately.