In a large mixing bowl, lightly mash the black beans. Add the ground beef and chopped cilantro, mixing gently until just combined.

Divide the mixture into 4 equal portions and shape them into round patties.

Preheat a grill or skillet over medium-high heat. Cook the patties for 4 to 5 minutes per side, or until they reach your desired level of doneness.

During the last minute of cooking, place a slice of cheddar cheese on each patty and let it melt.

Toast the hamburger buns until lightly golden brown.

Assemble the burgers by spreading creamy burger sauce on the bottom buns. Layer with fresh arugula, the cheesy black bean and beef patties, and red onion slices, then top with the upper bun.