Preheat the oven to 400 degrees F.

Peel and dice the sweet potatoes, toss with 1 tbsp. olive oil and pinch salt/pepper. Add sweet potatoes to a baking pan and roast for 30-40 minutes until soft

While the potatoes are cooking, make the rice. Set aside. 

In a food processor, add the oats, cumin, chili powder, paprika, cayenne and pulse 10 times.

Place the spice and oat mixture into a large bowl.

Add the sweet potato, brown rice, black beans, red onion and garlic to the bowl of the food processor and grind until combined and slightly chunky. You don't want it to be completely pureed but it should be able to stick together fairly easily.

Add the sweet potato mixture to the oat mixture along with the minced cilantro and stir together until combined. Place the mixture into the fridge for at least 20 minutes to cool and form an easier patty.

Preheat a non-stick pan (preferably cast-iron) to medium heat. Lightly oil with more olive oil or with cooking spray. 

Scoop out ~1/2 cup of the mixture and form into a patty. Place patty into the pre-heated pan and cook for 4-5 minutes per side until crispy and lightly-browned.

Place on toasted bun and serve with toppings of choice.