The Best Veggie Burger

Step 1
Preheat the oven to 450 degrees F (230 degrees C). Line a rimmed baking sheet with foil.

Step 2
Place mushrooms and onion on the prepared baking sheet. Drizzle with 1 tablespoon oil and toss to coat.

Step 3
Roast in the preheated oven for 10 minutes. Reduce heat to 425 degrees F (220 degrees C) and add black beans to the pan. Cook until mushrooms and onions are browned and beans are dried on the surface, about 5 more minutes.

Step 4
Remove from the oven and let mixture cool for 10 minutes.

Step 5
Transfer mixture to a food processor. Add rice and walnuts and pulse until roughly chopped. Add Worcestershire sauce, ketchup, soy sauce, garlic powder, paprika, chili powder, 1/2 teaspoon salt, and 1/2 teaspoon pepper and pulse until just combined. Add egg and pulse until just combined.

Step 6
Transfer mixture to a medium bowl and fold in bread crumbs until well mixed. Chill for 10 minutes.

Step 7
Form mixture into 8 patties and season each with salt and pepper.

Step 8
Heat 1 tablespoon oil in a large skillet. Add 4 patties and cook, undisturbed, until browned and a nice crust has formed, about 4 minutes. Flip and cook until done, 4 to 5 more minutes. Top with Muenster cheese and place on toasted buns.

Step 9
Add remaining 1 tablespoon oil to the skillet and repeat to cook remaining patties.