Cook the beans and noodles in salted water (separately). Meanwhile, chop the spring onions and grate the parmesan.
Mix the hot pasta with the parmesan in a bowl and add the beans and onions. Season to taste with pepper, salt and balsamic vinegar and let stand for 2 - 4 hours.
Then season again to taste and add olive oil. Finally, fold in freshly chopped parsley and possibly a few halved cocktail tomatoes - for the color.