Prepare a grill for medium-high, direct heat. Clean and oil grate. Shred 1 14-oz. block extra-firm tofu, drained using the large holes of a box grater. Firmly squeeze tofu in between paper towels to drain as much excess liquid as possible.
Heat 2 Tbsp. extra-virgin olive oil in a large nonstick skillet over medium. Cook tofu and 2 14.5-oz. cans black beans, rinsed, drained well, tossing occasionally, until beans look slightly dried out and their skins are darkened, 10–12 minutes.
Meanwhile, whisk ¼ cup almond butter and ¼ cup mayonnaise (vegan, if you are vegan) in a medium bowl until smooth. Whisk in 2 garlic cloves, finely grated, 4 tsp. chili powder (make sure it’s salt-free), and 4 tsp. Diamond Crystal or 2 tsp. Morton kosher salt. Add tofu-bean mixture and 2 cups cooked quinoa (we prefer red or black), cooled and stir well to combine.
Stir ¼ cup flaxseed meal and ¼ cup cold water in a small bowl. Let sit until a thick paste forms, about 1 minute. Add to tofu-bean mixture along with 2 Tbsp. cornstarch and stir well to combine.
Using oiled hands, form mixture into 8–10 patties about ½" thick (about a scant ¾ cup each). Grill until lightly charred around the edges, about 2 minutes. Turn carefully using a metal spatula to cleanly lift off grate and grill until lightly charred on second side and warmed through, about 2 minutes more.
Place burgers on bottoms of toasted buns. Pile high with pickled onions, tomato, lettuce, pickles, and chipotle yogurt. Close with top bun and serve. Do ahead: Patties can be formed 3 days ahead. Tightly wrap each in plastic and chill.
Editor’s note: This recipe was first published in June 2018. Head this way for more of our favorite vegetarian recipes →