In the meantime, heat the same skillet over medium heat. Once hot, add oil and onion. Season with a bit of salt and pepper and sauté for 3-4 minutes, or until onion is fragrant, soft, and translucent. Remove from heat and set aside.
Next add cooked rice, spice-walnut mixture, sautéed onion, panko bread crumbs, BBQ sauce, and mix thoroughly with a wooden spoon for 1-2 minutes, or until a moldable dough forms. If dry, add extra 1-2 Tbsp (amount as original recipe is written // adjust if altering batch size) BBQ sauce. If too wet, add more panko bread crumbs. Taste and adjust seasonings as needed.
For larger burgers, divide into 5 patties (1/2 cup in size // amount as original recipe is written), or form 10 smaller burgers (1/4 cup in size // amount as original recipe is written). To help form the patties, line your 1/2 or 1/4 measuring cup with plastic wrap and pack with burger mixture. Press down to pack firmly, then lift out by the plastic wrap’s edge, and slightly flatten with hands to form a 3/4-inch thick patty. Set on a baking sheet or plate for grilling.
Once skillet is hot, add just enough oil to lightly coat the bottom of your skillet, then add your burgers - only as many as will comfortably fit in the pan. Otherwise, add burgers to the grill and close lid.
*To cook rice, I recommend this method from Saveur. It yields fluffy, perfect rice, which is key to keeping these burgers from becoming too wet or gummy in texture. // Prep time does not include cooking rice.
*One 15-ounce (425 g) can of black beans yields only 1 1/4 cups black beans. So if using canned, be sure to grab two cans (amount as original recipe is written // adjust if altering batch size)! Also, if black beans are unsalted, add 1/4 tsp extra salt to burger mixture (amount as original recipe is written // adjust if altering batch size).
*For a simple burger sauce mix 2 parts vegan mayo and 1 part ketchup. Add hot sauce or Sriracha for extra heat.
*To freeze for later, cook burgers as instructed on grill or skillet. Then set on a baking sheet or plate and freeze. Once frozen completely, seal in a freezer-safe bag or container and store for up to 3 weeks. Reheat in a 375 degree F oven on a bare baking sheet for 20-30 minutes, or until warmed through and golden brown (or in the microwave for 1-2 minutes).
*Nutrition information is a rough estimate calculated with the lesser amount of BBQ sauce and without a bun or toppings.