You can use any combination of vegetables you like for this. I'd always include a small onion. If using wet vegetables like zucchini or potato squeeze excess water out before adding. I specify packaged breadcrumbs because their dryness really helps absorb any excess moisture. These can be made in any size. The half cup measures work perfectly as 'burgers' for serving in a bun with humus and salad.
Recipe posted by Coby