To make flax egg, mix ground flaxseed with water in small bowl. Let sit 10 minutes to thicken.

In medium skillet, heat olive oil over medium heat. Add red onion and garlic, and sauté until softened (about 3–4 minutes). Remove from heat.

In large bowl, mash black beans with fork or potato masher, leaving some texture.

To mashed beans, add cooked quinoa, grated beet, walnuts, hemp seeds, arrowroot flour, basil, chopped spinach, sautéed onion/garlic, flax egg and spices. Mix well until fully combined.

Shape into 6 burger patties and place them on a parchment-lined tray.

Preheat skillet with olive oil over medium heat. Cook burgers 4–5 minutes on each side until browned and firm. If baking is your preference, bake at 375 degrees F for 25–30 minutes, flipping halfway.

Serve on bun or lettuce wrap with avocado, tomato, mustard or your favorite toppings.