*For vegetarian diets, make sure the Worcestershire sauce you choose does not contain anchovies
Heat oil in a large pot over medium high heat. Add peppers, onion, mushrooms and garlic; saute for 3 minutes or until tender. Add 3 cups water, corn, sugar, chili powder, Worcestershire sauce, tomatoes, black and cannellini beans and stir to combine. Combine remaining cup of water and tomato paste in a bowl, stirring with a whisk until blended. Stir tomato paste mixture into bean mixture. Bring to a boil, then reduce the heat and simmer for 5 minutes or until thoroughly heated. Ladle soup into bowls. Top with cheese, if desired.