- 2 15-oz. cans black beans, drained and rinsed
- 1/2 medium yellow onion, chopped
- 2 cloves garlic, minced
- 1 large egg
- 1/2 c. plus 2 tbsp. mayonnaise, divided
- 3/4 c. panko bread crumbs
- kosher salt
- Freshly ground black pepper
- 2 tbsp. canola oil
- 4 slices white cheddar
- 3 tbsp. ketchup
- 4 Hamburger buns
- 1 tomato, sliced
- 4 Romaine lettuce leaves
- In a food processor, pulse black beans, onion, and garlic until finely chopped.
- Transfer to a large bowl and combine with egg, 2 tablespoons mayo, and panko. Season generously with salt and pepper and form the mixture into 4 patties. Refrigerate until firm, about 15 minutes.
- In a large skillet over medium heat, heat oil. Add patties and cook until golden and warmed through, about 5 minutes per side.
- Top each patty with a slice of cheese and cover the skillet to melt.
- In a small bowl, whisk together ketchup and remaining mayo. Spread mayo mixture onto the bottom of the buns, then add burgers. Top with tomato, lettuce, and remaining bun halves.