Rinse and drain the black beans, then pat them dry with a paper towel to ensure the burgers hold their shape.
In a medium bowl, mash the black beans with a fork until they form a thick paste with some whole beans remaining for texture.
Add the egg whites, nutritional yeast, hemp hearts, minced red onion, cumin, smoked paprika, sea salt, and black pepper to the beans and stir until well combined.
Divide the mixture and form into two equal-sized patties, pressing firmly so they stay together during cooking.
Heat the avocado oil in a large non-stick skillet over medium-high heat.
Carefully place the patties in the skillet and cook for 5 to 6 minutes per side until a golden-brown crust forms and the center is firm.
While the burgers cook, whisk together the nonfat Greek yogurt and lime juice in a small bowl to create the sauce.
Arrange the baby arugula on a plate, place the burgers on top, and finish with a generous drizzle of the lime-yogurt sauce.