Wash your beet and (follow link for easy boiling directions) Let cool. Then slice.
Preheat oven to 375F. Line a large rimmed baking pan with parchment paper and then spray parchment paper with cooking spray.
Drain and rinse black beans. Reserve 1/4 cup of beans.
Slice your white onion into medium sized chunks.
Add all ingredients except reserved black beans and breadcrumbs to your food processor. Pulse lightly until mixture is combined. You don't want a puree but you do want all pieces to be combined.
Transfer mixture to bowl. Stir in breadcrumbs, brown rice flour and reserved black beans.
Shape mixture into patties (I made 6) and place on prepared baking pan. Bake for 20 minutes, then carefully flip. Cook another 10 minutes. After removing from oven, let rest for 5 minutes so they 'firm'. If you want additional 'crisp' - crisp them up on your stovetop in a medium sized skillet.
Top with lettuce, tomatoes, red onion, avocado or ! Eat in a bowl or on a bun.
These can be meal prepped and are a great freezer meal. For freezing, cook as directed, let cool, then place in freezer safe container and freeze until ready to use. When ready to use, remove from freezer and reheat on stovetop (for crispy) or microwave (will be softer).