Drain and rinse the chickpeas (if they are canned, 4 cups = 2 cans) and put them, along with all the other ingredients, in a blender or food processor. (The paste needs to be thick enough to hold up as a patty, so if you have to use less liquid, that's okay.) Pulse, scraping down the side of the bowl, to form a coarse paste. Scrape the paste into a bowl.