01 -
Cook the green beans in boiling water or steam them. Keep an eye on them so they stay a little firm. Drain and let them cool down.
02 -
In a big bowl, mix together drained corn, tuna chunks, black olives, croutons, halved cherry tomatoes, and thinly sliced fresh onions.
03 -
Take the cooled green beans and toss them into the big bowl with the other ingredients.
04 -
In a small bowl, whisk together the olive oil, balsamic vinegar, plus as much salt and pepper as you like.
05 -
Pour the dressing over everything in the bowl, mix it well, and chill until you're ready to serve.