When the onion becomes soft and transparent enough (it took me about 30 minutes, depending on the depth of the pan), add salt, sugar, pepper. pour the wine. Add a bouquet of Garnishes, well tied with twine, which did not fall apart during cooking. These are rosemary, thyme, bay and celery. Simmer for about 2.5-3 hours. Stir constantly so that the onion does not burn.