Place the garbanzo beans, onion, and potato in the bowl of a food processor. Cover, and process until finely chopped. Leaving about 1 cup of the garbanzo bean mixture in the food processor bowl, pour the rest into a mixing bowl. Add the garlic, cilantro, coriander, cumin, salt, pepper, and cayenne pepper to the garbanzo bean mixture in the food processor bowl; process on low to blend thoroughly. Return the reserved garbanzo bean mixture to the food processor bowl, and add the lemon juice, olive oil, and flour; process on low into a coarse meal. Cover, and refrigerate 2 hours.