Heat oil in a large skillet over medium heat, cook green onion, red pepper, garlic until slightly soft, about 2 minutes. Add the rice, quinoa, and black beans, stir well.
Add the stock and the spices to the mixture and bring it to a gentle boil. Reduce the heat to low and cover, simmer for 15-20 minutes or until the rice and quinoa are tender.
When done, stir everything in the skillet and season with salt and pepper if needed.