In a small saucepan over medium heat, vegetable broth and tomato sauce. Bring to a boil while cooking the following.
Add onion to skillet, and saute until tender. Stir in rice, and cook until lightly browned, 3 to 5 minutes. Pour in boiling chicken broth and tomato sauce. Add diced tomatoes, green peppers. Season with chili powder, salt, and pepper. Cover, and simmer for 30 to 40 minutes. Stir in black olives and corn.