Preparation

• Process beans, oats, garlic, soy sauce, and chili powder in a food processor until ingredients begin to come together, about 30 seconds.
  
  Transfer bean mixture to a large bowl and stir in scallions.
  
  Shape mixture into 4 (¾-cup) patties, and then let them stand at room temperature 5 minutes or refrigerate up to 3 hours.
  
  Heat oil in a large nonstick skillet over medium-high. Cook patties in hot oil until browned, about 5 minutes per side.
  
  Place 1 patty on each hamburger bun bottom, and top each with ¼ cup salsa. Add lettuce, tomato slices, and red onion slices, and cover with bun tops.