Directions:

1.  Black Bean, Rice and Walnut Patties: Heat sauté pan over medium high heat. Add walnuts. Toast both sides for 5 to 6 minutes. Heat oil in a sauté pan on medium high. Add onions, salt and pepper. Saute until softened with light brown edges. In a food processor, add walnuts, chili powder, cumin, paprika and brown sugar. Pulse until fine. In a bowl, add beans, using the back of a serving spoon, mash beans until thick and pasty leaving a few whole. Add rice, walnuts, onions, bread crumbs and bbq sauce. Mix until thoroughly incorporated. Make into 6 patties.
2. Frizzled Onions: In a bowl, combine flour, salt, black pepper and cayenne pepper. Mix well. Soak onions in buttermilk. Drain well. Dredge onions in flour mixture, shake off excess flour. Deep fry at 350 degrees until golden brown and crispy. Drain well on paper towels.
3. For Service: Toast cut side of hamburger buns. Place patty on heel of bun. Place 2 tablespoons onions on top of patty. Place 2 slices avocado on top of onions. Spread bbq sauce on crown of bun. Close sandwich with crown.