Pulse the beans in a food processor until coarsely chopped, then transfer to a large mixing bowl. Pulse the walnuts in the food processor until finely chopped, then transfer to the bowl with the beans. Add the panko, 1 teaspoon salt, the onion powder, garlic powder, 1/4 teaspoon pepper, the egg and 2 tablespoons of the barbecue sauce and mix well. Divide the mixture into 4 equal parts. Shape into patties and refrigerate for 30 minutes.
Heat a nonstick skillet over medium heat. Add the olive oil. Brush the tops of the burgers with the remaining 1 tablespoon barbecue sauce. Cook the burgers sauce-side up for 3 minutes. Flip and top each with a slice of cheese, if using. Cover and cook until the cheese is melted and the burgers are heated through, about 3 minutes. Serve the burgers on the buns with desired toppings.
Stovetop
2023