In a large saucepan over high heat, combine the chickpeas, water, garlic cloves, bay leaf and 1/4 teaspoon of salt. Bring to a boil. Reduce the heat to low, cover partially and simmer until the beans are very tender, 50 to 60 minutes. Drain and discard the bay leaf, reserving the garlic and 1/2 cup of the cooking liquid.
In a blender or food processor, combine the chickpeas, cooked garlic, olive oil, 3/4 cup green onion, vinegar, cilantro, cumin and the remaining 1/4 teaspoon salt. Process to puree. Add the reserved cooking liquid, 1 tablespoon at a time, until the mixture has the consistency of a thick spread.
In a small serving bowl, stir together the chickpea mixture and the remaining 2 tablespoons green onion. Serve immediately, or cover and refrigerate until ready to serve. Makes about 1 1/2 cups.