Mash beans in a large bowl.
Stir in oats, green onions, and next 5 ingredients.
Shape mixture into 10 (4-inch) patties.
Cook half of patties in 2 tablespoons hot oil in a large skillet over medium-high heat 2 to 3 minutes on each side or until lightly browned.
Repeat with remaining patties and oil.
Serve on warm buns with desired toppings.