Combine the quinoa, water, and ½ teaspoon salt in a small saucepan with a lid. Bring to a boil, lower the heat to low, cover the pan, and simmer for 10-15 minutes or until all the water has been absorbed. Remove from heat and let sit, covered, for 5 minutes. Fluff with a fork. (Alternatively, you can use 2½ cups already cooked quinoa.)

Place half of the black beans in a food processor with the ground cumin, green onions, 1/3 cup vegan mayonnaise, and ¼ teaspoon pepper. Process until the mixture is smooth. Add the remaining beans and pulse a few times until you have a somewhat chunky puree. Transfer the bean mixture into a mixing bowl. Add the cooked quinoa and 6 tablespoons of flour. Stir to combine. Place the remaining ½ cup flour on a dinner plate. Portion the bean mixture into 6 equal sized patties.

Add just enough oil to coat the bottom of a large skillet. Heat over medium-high until it starts to shimmer. Place the patties into the flour and coat both sides. Add the patties carefully to the hot skillet. Do not over-crowd the skillet. Cook for 3-4 minutes per side or until golden brown.

Combine the remaining 1/3 cup vegan mayonnaise with the chipotle chili powder. Place the burgers on lettuce leaves and top each with a dollop of the chipotle mayonnaise.