As I promised in the introduction, we are going to try now with one of those jams that are very topical: that of red onion. I am going to make it at the request of Manolo (the husband of María José, the fruit bowl) who gave me the onions and gave me the following recipe, albeit without quantities: red onion, sugar, salt, pepper and Modena vinegar. From what I have investigated it is served with a good foie spread on bread, a slice of ham and jam on top; It also looks great on a nice piece of grilled meat.
1 k. onions
200 or 300 g of brown sugar, depending on how sweet you want it
a nice touch of ground white pepper (one tablespoon)
salt to taste
4 tablespoons packed with Modena vinegar
I think that all the recipes that I have seen put optional values and emphasize that it will depend on the taste of each person. For example, I think I would add more pepper than I put; otherwise, it seems to me to be delicious.