Step 1

1 In the bowl of a food processor, combine the beans, mushrooms, oats, tamari, paprika, garlic powder, black pepper and 1/4 teaspoon of salt and pulse until the mushrooms are finely chopped and the mixture is evenly combined, 10 to 15 seconds

Step 2

2 (Alternatively, use a fork to mash the beans in a large mixing bowl until mushy but not totally smooth

Step 3

3 Chop the mushrooms by hand

Step 4

4 Add the mushrooms and the remaining ingredients to the beans and stir until evenly combined

Step 5

5 ) Form the mixture into 4 patties that are about 3 1/2 inches in diameter, using about 1/2 cup of the mixture for each

Step 6

6 Let sit for 10 to 15 minutes while you make the onions

Step 7

7 In a large skillet over medium heat, heat 1 tablespoon of the oil until it shimmers

Step 8

8 Add the onions and the remaining 1/4 teaspoon of salt and cook, stirring regularly, until the onion begins to soften and turn translucent, about 10 minutes

Step 9

9 Add the vinegar and cook, stirring regularly, until it reduces and coats the onion, about 3 minutes

Step 10

10 Transfer to a small bowl

Step 11

11 In the same skillet, add the remaining 2 tablespoons of the oil, increase the heat to medium-high and heat until the oil shimmers

Step 12

12 Add the burgers and cook until nicely browned, about 4 minutes per side

Step 13

13 Serve on buns, topped with some of the balsamic-glazed onions along with cheese, lettuce, slices of tomato, pickles, mustard and/or ketchup, if desired