Some good binding agents/fillers include; Oatmeal (my favorite), grape nuts, flour or vital wheat gluten and veggies (if someone has a juicer and you can get your hands on the dry veggie pulp of like celery and carrot and such, that’s the way to go), breadcrumbs/panko
You need a binding agent of some sort, but yeah
Black bean burgers are pretty damn good
Some good binding agents/fillers include; Oatmeal (my favorite), grape nuts, flour or vital wheat gluten and veggies (if someone has a juicer and you can get your hands on the dry veggie pulp of like celery and carrot and such, that’s the way to go), breadcrumbs/panko