Soak the chickpeas overnight in salted water (about one handful of salt) in order to soften them.

Rinse thoroughly the next day.

Lightly sauté the onion in the oil, add the chickpeas and in a few moments add hot water so that it covers them, salt, pepper and let everything boil till they are cooked.

Dissolve the flour in the lemon juice and add it to the food in the last 10 minutes. When the chickpea soup thickens, remove from heat and serve.