Heat olive oil in a large cast-iron pot (cauldron) over medium-high heat. Pour onion and garlic into a saucepan, fry, stirring occasionally, for about 5 minutes, until the onions are soft. Then put the green beans, carrots, white beans, and tomatoes in a saucepan, pour over the broth, bring to a boil. Place the pasta in a saucepan, cover, reduce heat and cook the bean and pasta ragout for about 12 minutes, until the pasta is done.
Then add basil, oregano, tomato paste, and black pepper into a saucepan. Place the fish in a saucepan and cook the bean stew for 3 minutes.
Serve stew with beans in portioned bowls, sprinkle with cheese.