Mash the steamed sweet potato, black beans, and flax eggs first.
When it's all smooth, add the green chilis, nutritional yeast, and spices.
Add 1/3 cup potato flour and keep adding to your liking. My burgers were soft, but for firmer burgers go heavy on potato flour. It absorbs more liquid making a firmer burger patty.
Form patties in your hand and lay on a parchment paper lined tray. Cover with another layer of parchment paper and freeze overnight.
When you are ready to serve, fry patties in a skillet with olive oil until crispy on both sides and fix up a burger to your likin'!