Other ideas for what to add to the
mixture:
zucchini, squash, sweet potatoes, mushrooms, swiss chard, flax seed, walnuts,
quinoa, pistachios, oats, pumpkin seeds or beans.
Two things I think could help — making sure to ring out the excess liquid in the
zucchini (after grating it) by squeezing it through a cheesecloth or towel and also adding a bit of flour (
quinoa flour for example) to the
mixture should help these stay together.