1. Preheat oven to 350° F. Grease or cover a baking sheet with parchment paper. 

2. Drain the liquid from the black beans and spread them out on the baking sheet. Place them in the preheated oven for 8 minutes to evaporate the liquid and partially dry them out. Pull the black beans from the oven and immediately transfer to a mixing bowl. Use a potato masher to mash the beans, leaving only a few whole. 

3. Finely dice half of the onion (you’ll have about 1/2 cup) and prepare the garlic, carrots, and pepper.

4. Make the breadcrumbs.  

5. In a small bowl, whisk together the tapioca flour and water; add the hot sauce and seasonings and stir into the mashed beans.

6. Add the breadcrumbs and the nutritional yeast to the bean mixture and stir until well combined. 

7. Scoop a ½-cup mound of bean mixture onto the prepared baking sheet and shape into a burger, ½-¾-inch thick. Repeat until you have 6-8 burgers. 

8. Bake for 20-25 minutes, or until the center begins to firm up and the outside is crisp. 

9. While the burgers cook, prepare the toppings. Slice the remaining half of red onion thinly into half-moons. Make the chili-lime aioli by mixing together all ingredients in a small bowl. 

10. Just before the burgers are done, toast the buns (on a baking sheet in the oven, on the grill, or in a toaster) and divide the aioli evenly among the buns, brushing both sides of each bun. 

11. To assemble, place a burger on each bun, top with onion slices, tomato, and additional toppings of your choice. Serve immediately.