Grilled Black Bean Veggie Burgers

For oil-free: In a large skillet cook the beans, onion, garlic, paprika, and pepper over medium until onion is tender, stirring occasionally. (If using oil: Heat a large skillet over medium and lightly coat with avocado oil. Add the next five ingredients, through pepper, and cook until onion is tender, stirring occasionally.) Coarsely mash bean mixture; cool slightly. 2. Meanwhile, in a large bowl stir together flaxseed meal and ⅓ cup water. Let stand 15 minutes. 3. Stir tomato sauce and soy sauce into flaxseed mixture. Add bean mixture, brown rice, and panko. Stir to combine. Divide into eight portions. Form into ¾-inch-thick patties. 4. Grill, covered, over medium heat 5 minutes. Carefully turn burgers and grill 5 minutes more or until heated through. Brush with water if needed to prevent sticking. Serve burgers on buns with desired toppers.