Our local town, Certaldo, had been famous for almost a thousand years for its delicious red onions. In the last few years a group of local farmers, supported by the Slow Food Foundation and the City Hall has been growing them and popularising them again. They are used in many dishes; one of the most popular is this simple, warming soup.
- 4 large red onions (mild if possible), approx 1 kg, ½ lb
- Vegetable stock , 1 litre (1 quart)
- 1 medium potato, peeled and cut into half inch cubes
- Extra virgin olive oil
- Rustic style bread (sourdough is good)
- Salt, pepper
- Peel the onions and slice them.
- Add to 2 tablespoonfuls of cold extra virgin olive oil in a pot and soften on a low-medium heat, moving around so that the onions do not burn. Cook until some are golden (10 minutes approx).
- Add the hot vegetable stock and the potato. If the stock is unsalted, add half a teaspoon of salt. The stock should easily cover the vegetables. If it does not, boil water and add until they are well covered.
- Cook with the lid on the pot on a medium heat until the onions and potatoes are very soft. Make sure that the liquid level is always covering the vegetables. Add more boiling water if necessary. (20-30 minutes). Turn off the heat.
- Either sieve the soup or use a hand-blender to blend it. Either way, you will get a smooth creamy soup.
- Serve with slices of toasted rustic bread, a good drizzle of extra virgin olive and plenty of freshly ground black pepper.