serves 6
Chickpeas, one of the oldest legumes found in the eastern Mediterranean, continue to be an important food in the Cyclades, especially on the island of Sifnos, where to this day a clay pot–baked chickpea soup is the Sunday meal. Home cooks fill their xespastaria—a unique clay pot with a wide bottom and narrow, tapered mouth—with the ingredients for a traditional revithada, or chickpea soup, and bring the pots to the local baker, who heats the vessels overnight in a hot, but not fully fired, wood-burning oven. The next day, usually after church, people pick up their blackened pots to take home for the family meal. Sometimes rice or dried corn is added to make the soup more filling. Note that the chickpeas need to soak overnight, so plan ahead.
1 teaspoon baking soda
1 pound (450 g) dried chickpeas, picked over for debris and rinsed
2 large red onions, coarsely chopped
6 garlic cloves, minced
2 large carrots, cut into ½-inch (1.5 cm) cubes
2 celery stalks, chopped
1 cup (240 ml) extra-virgin Greek olive oil, plus more for seasoning the finished soup
3 bay leaves
2 fresh rosemary sprigs
Salt
3 tablespoons strained fresh lemon juice or red wine vinegar
Dissolve the baking soda in a large bowl of cold water, add the chickpeas, and soak in the refrigerator overnight. Drain and rinse very well.
Place the chickpeas in a large pot and add cold water to cover by 3 inches (7.5cm). Bring to a boil over medium heat, then reduce the heat to maintain a simmer and cook the chickpeas until they are al dente, about 1 hour, skimming off any foam from the top as they cook.
Preheat the oven to 350ºF (175ºC).
Remove the pot of chickpeas from the heat. Using a slotted spoon, transfer the chickpeas to a large ovenproof clay or earthenware pot with a tight-fitting lid, reserving their cooking liquid. Add the onions, garlic, carrots, celery, olive oil, bay leaves, and rosemary, season with salt, and add enough of the reserved chickpea cooking liquid to cover the ingredients by 3 inches (7.5 cm). Cover the pot and transfer to the oven.
Bake for 2 hours, or until the chickpeas are very soft. Remove from the oven. Remove and discard the bay leaves and rosemary. Ladle 2 cups (480 ml) of the soup into the bowl of a food processor and puree until smooth, or ladle it into a medium bowl and puree with an immersion blender until smooth. Return the pureed soup to the pot. Season with salt, lemon juice or vinegar, and olive oil to taste. Stir well to combine.
Taste and adjust the seasoning with additional salt, additional lemon juice or vinegar, and olive oil. Serve hot.