In a large saucepan cook and stir onion and garlic in hot oil over medium heat for 5 minutes or until tender. Add tomato sauce, black beans, great Northern beans, diced tomatoes, soybeans, chile peppers, water, and vinegar. Bring to boiling; reduce heat. Simmer, covered, for 20 minutes, stirring occasionally. Stir in olives and cilantro. Simmer, covered, for 5 minutes. Ladle into bowls over rice, pasta, or couscous; top with mozzarella cheese, if desired. Makes 6 servings.