Preheat oven to 400 degrees F (204 C) and cut sweet potatoes in half. Rub with olive oil and place face down on a foil-lined baking sheet. Bake sweet potatoes until soft and tender to the touch – about 30 minutes – set aside. Reduce oven heat to 375 degrees F (190 C). While potatoes are baking, cook rice.
Add black beans to a mixing bowl and mash half of them for texture. Then add sweet potato and lightly mash, then 1 cup rice (amount as original recipe is written // if altering batch size, start with lesser end of range), green onion, nut meal and spices. Mix to combine. Taste and adjust seasonings as needed. Add more rice or nut meal if the mixture feels too wet. It should be very moist but moldable. Lightly grease a baking sheet and line a 1/4 cup measuring cup with plastic wrap.
Fill the lined measuring cup with sweet potato mixture. Scrape down to pack, then lift out and transfer to the baking sheet and gently press down to mash. The thinner you press them, the faster they’ll cook, but no need to go too far. A gentle press will do.
Bake burgers for a total 30-45 minutes, carefully flipping 20 minutes in to ensure even cooking.
Serve on slider buns (double stack for more bulk) or atop a salad with sliced avocado, red onion,greens, and ketchup or salsa.
