1Drain and rinse the canned black beans thoroughly. Transfer to a food processor with diced onion, bell pepper, cilantro, and garlic. Pulse until combined but still chunky—you want texture, not a smooth paste.
2Transfer the mixture to a mixing bowl. Add panko breadcrumbs, juice from the lime, cumin, smoked paprika, cayenne, salt, and black pepper. Stir until everything is evenly incorporated.
3Divide the mixture into 4 equal portions. Form each into a patty about 3/4 inch thick. The mixture will be somewhat delicate, so handle gently.
4Heat vegetable oil in a skillet over medium-high heat. Once shimmering, carefully add the patties and cook for 4 to 5 minutes on the first side without moving them—you want a golden crust to form. Flip gently and cook another 3 to 4 minutes on the second side until both sides are crispy.
5Toast the hamburger buns lightly if you like. Build your burgers: bun, lettuce, burger patty, tomato slice, avocado slice, top bun.