Preheat the Griddle: Set your Blackstone griddle to medium-high heat. Add the black beans (no oil needed) to the griddle. Cook for about 5 minutes, allowing the beans to dry out and crack open. Remove from the griddle and place in a blender or food processor.
Blend the Ingredients: Add the bread crumbs, nutritional yeast, and Chicago Steak seasoning to the blender. Pulse until the beans are broken down. Transfer the mixture to a bowl, then add the egg (or egg substitute) and cornstarch. Mix until you can form the mixture into a ball. Divide into 4 equal-sized balls.
Cook the Patties: Add a bit of oil to the griddle. Place the 4 black bean balls onto the griddle. Top each with parchment paper and smash into patties. Remove the parchment paper and season with additional Chicago Steak seasoning. Add a pile of onions to each patty and flip.
Add Mustard and Cheese: Spread 1 tsp mustard on each patty. After cooking for 2-3 minutes, flip the patties again, then top each with a slice of cheddar cheese and pickles.
Assemble the Burgers: Once the cheese has melted, stack 2 patties together and place on a bun.
