Heat the vegetable oil in a large saucepan over medium-high heat. Stir in the quinoa, onion, garlic, and green pepper. Cook and stir 5 to 10 minutes until the onion is tender, and the quinoa has lightly toasted. Stir in the tomato sauce and water, then season with the chili powder, garlic powder, and cumin. Bring to a boil, then reduce heat to medium-low, cover, and simmer until the quinoa is tender, and the liquid is absorbed, about 30 minutes. Stir the quinoa occasionally as it cooks.