OK - this is a problem that many people encounter. It seems to be totally random. Sometimes they work out perfectly and other times they 'fall apart’. Because it is random I 'ALWAYS' take the smallest amount of mixture and test in hot oil. If it falls apart then I know this early. What I do is; I add flour, generally chickpea flour will do the trick, depending on the amount of mixture, I add about 2-3 tablespoons. I would also add (if the recipe doesn't include) some bulgur wheat and some baking powder. So the flour offers a binding solution, as does the bulgur, but the baking powder controls the cooked consistency.