I'm really proud of this one. My hubby loves them with cheese and my Smoky & Spicy BBQ sauce in sandwiches. I just can't believe I came up with this recipe. The day I came up with it I didn't have egg, so I would say the egg is optional. The way you can have your crumbs stick a little better to the patties is by using a little bit of mustard. The end product won't look golden brown (especially without any oil and with the panko) but they will taste delicious and they will be healthy.