In large saucepan, heat remaining 2 tsp oil. Remove sausage from casings and add to pan, breaking meat into pieces. Heat until sausage is cooked through. Add chili powder, oregano, and cumin to pan; heat 30 seconds. Place 6 cups water, quinoa, black beans, and cooked vegetables along with any juices into saucepan. Bring to a boil, reduce heat to medium-low, and simmer for 15 minutes, or until quinoa is tender. Add corn to pan and heat 1 minute.