Finely slice the white half of the leek (save the green part for another recipe). Place in a large pan on a low heat with 2 tablespoons of olive oil and 2 tablespoons of water. Cook for 15 minutes, stirring regularly.
Tip in the chickpeas (juice and all), then pour in half a jar's worth of water and turn the heat up to medium. Peel and add the garlic cloves whole, then cook for a further 30 minutes, or until reduced to a nice saucy consistency.
Finely chop the parsley, stir into the pan, season to perfection, and finish with a drizzle of cold-pressed extra virgin olive oil.