Heat the oil in a large, heavy pan, then add the onion and sauté gently for 10–15 minutes, until it starts to colour.

Meanwhile, drain the chickpeas, rinse them under cold water, and drain them again. Shake the colander or strainer to dry the chickpeas as much as possible, then add them to the pan.

Turn them with a spatula for a few minutes to coat them well in the oil, then pour in enough hot water to cover them by about four centimeters/one and a half inches.

Slowly bring to the boil. Skim off any froth that rises to the surface, using a slotted spoon, and discard. Lower the heat to a simmer, add some pepper, cover, and cook for one hour to an hour and fifteen minutes, or until the chickpeas are soft.

Put the flour in a cup and stir in the lemon juice. When the chickpeas are soft, add this mixture to them. Mix well, then add salt and pepper. Cover the pan and cook gently for five to 10 minutes more, stirring occasionally.

To thicken the soup slightly, take out about two cupfuls of the chickpeas and put them in a food processor or blender. Process briefly so that the chickpeas are broken up, but remain slightly rough. You could also use a fork. Add these to the soup in the pan and mix well.

Add the parsley, then taste the soup and add more lemon juice if it is bland. Ladle into bowls and offer extra olive oil at the table.