Have you tried lentils? They're a hearty, yet mild tasting legume that is packed with fiber and nutrients. Below is a recipe by Food Network's Giada De Laurentiis that I altered a bit to produce a more broth-y soup with plenty of Parmesan flavor.
2 tablespoons olive oil, extra for drizzling
1 medium onion, chopped
2 carrots, peeled and chopped
2 celery stalks, chopped
2 garlic cloves, chopped
Salt and freshly ground black pepper
1 (14 1/2-ounce) can diced tomatoes
1 pound lentils (1 regular size bag), rinsed well
13+ cups low-salt chicken broth
4 to 6 fresh thyme sprigs (or a couple teaspoons of dry thyme)
2/3 cup dried elbow pasta (or any short pasta you like)
1 cup shredded Parmesan
Heat the oil in a heavy large pot over medium heat. Add the onion, carrots, and celery. Add the garlic, salt, and pepper and sauté until all the vegetables are tender, about 5 to 8 minutes. Add the tomatoes with their juices. Simmer until the juices evaporate a little and the tomatoes break down, stirring occasionally, about 8 minutes. Add the lentils and mix to coat. Add the broth and stir. Add the thyme sprigs. Bring to a boil over high heat. Cover and simmer over low heat until the lentils are almost tender, about 30 minutes. You'll need extra broth for the pasta, so if there's not a lot of broth left after simmering, add more and bring to a simmer again. Stir in the pasta. Simmer until the pasta is tender but still firm to the bite, about 8 minutes. Add about 1/2 cup of the Parmesan into the soup and stir well. Season with salt and pepper, to taste. Ladle the soup into bowls. Sprinkle with the Parmesan and serve.