In a large pot over medium heat, add oil to the pot. Add onions and garlic and occasionally stir for 3-4 minutes until onions are translucent. Add brown rice, stir for approx. 1 minute. Add stock, cover pot and lower heat, cook for approx. 35-40 minutes. Once rice is cooked, add spices, black beans and stir. Garnish with slivers of scallion as desired.