Cook the pasta in salted water until al dente. Add to the salad, otherwise they will be too soft afterwards.
In a large bowl, mix the beans, corn, bell peppers, tomatoes, and onions. Add the tuna with some of the stock - depending on your taste.
Pluck the leaves of the basil and roughly chop. Add to the other ingredients and fold in.
Put the warm, not rinsed noodles in the bowl and mix everything well. Add the balsamic vinegar and olive oil so that the ingredients are wetted but not float.
Season with salt and pepper and, if necessary, a little sugar or sweetener (because of the vinegar; the salad then tastes rounder) and let it steep for at least 3-4 hours.
Tastes good with grilled food but also at lunchtime, e.g. at work.