To turn the soup mix into a pot of soup: Heat 1 tablespoon extra-virgin olive oil in a Dutch oven over medium heat. Add 1 diced large onion, 1 diced celery stalk and 1 diced carrot; cook, stirring occasionally, until softened, about 5 minutes. Add 9 cups water, 4 cups broth and the soup mix. Bring to a lively simmer over high heat. Reduce heat to maintain a simmer and cook, stirring occasionally, until the beans are tender, 1 3/4 to 2 1/2 hours (adding more water, 1/2 cup at a time, if necessary or desired). Season with 3/4 teaspoon salt, or to taste.