Spread out parchment paper onto a sheet pan. Rinse and drain the black beans and then pat dry with a paper towel. Spread the beans out onto the baking sheet and bake for 10-15 minutes, or until they dry out and begin to split open.
While the beans are baking, heat 1 teaspoon of oil in a small nonstick skillet over medium-high heat. Add the onions and saute until softened about 3 to 4 minutes. Add the mushrooms and saute for another 2-3 minutes. Blot off excess moisture on the onions and mushrooms, using a paper towel.
Add the beans, sauteed mushrooms, and onions, egg, ⅓ cup breadcrumbs, paprika, salt, and Worcestershire sauce to a food processor fitted with the s-shaped blade. Pulse the mixture until just combined but some chunks of beans remain intact. If the mixture is still fairly wet, add another tablespoon or two or breadcrumbs and mix it in by hand.
Divide the mixture into 4 equal portions and form into burger patties. Place onto the parchment paper lined sheet pan (you can reuse the parchment from cooking the beans.)
At this point you can bake the burgers at 375 degrees for 20 minutes, flipping the burgers after 10 minutes.
To Grill or Pan-Fry Black Bean Burgers
Place the prepared burgers into the freezer for 10-20 minutes to firm up to help keep their shape. Grill the burgers over medium-high heat on an oiled grill for 4-5 minutes per side. Or pan-fry in a greased nonstick skillet for 4-5 minutes per side.
Egg-Free Black Bean Burgers: In place of the egg, use 1 tablespoon ground flaxseed mixed with 3 tablespoons water or ¼ cup pureed sweet potatoGluten-Free Black Bean Burgers: Use gluten-free panko bread crumbs or oats. Also, be sure your Worcestershire Sauce is gluten-free or use coconut amino acids. Vegan Black Bean Burgers: In place of the egg, use 1 tablespoon ground flaxseed mixed with 3 tablespoons water or ¼ cup pureed sweet potato. In place of the Worcestershire Sauce, use soy sauce or coconut amino acids.Freezing Burger Patties:You can also freeze the uncooked burgers by placing them in between layers of parchment and sealing them in a freezer-safe bag. Grill from frozen over medium heat or bake at 375 degrees for 15 minutes per side, or until warmed through.Prepare without a Food Processor: If you don't have a food processor, use a fork to mix together all the ingredients BUT the beans. Once combined, add the means and use the fork to mash the beans up slightly as you combine the mixture.Leftovers: Allow burgers to cool and then store in an air-tight container for up to 4 days in the refrigerator or freeze for up to 3 months. It is best to reheat under a pre-heated broiler or in a dry skillet for a few minutes to retain the texture of the burger.