Crush the almonds in a mortar and leave them to soak in the vinegar with the cinnamon stick for about one hour. Finely chop the onions and fry in the oil. Rinse the almonds in a sieve and add to the onions. Add the sugar, salt and stock and cook for half an hour. Toast the slices of bread, place a slice in each dish and pour over the onion soup. You could garnish the soup by sprinkling grated Gruyère cheese over just before serving, or even return it to the oven for ten minutes, with the cheese on top. Onions are one of the basic ingredients in all Italian cooking and even the ancient Etruscans were aware of their medicinal properties, especially for curing inflamation. The Roman cook, Apicius, (Ist century A.D) used them in a recipe for hot broth.

According to Bartolomeo Sacchi, they "...encourage lust, their strong, agreeable flavour favouring its impulse...". This dish was very popular during the Middle Ages and the Renaissance, and is mentioned by both the Anonimo Toscano and Cristoro di Messi.