- 2 (6 ounce) cans tuna packed in oil
- 3 cups drained and rinsed canned white beans, preferably cannellini
- 1 red onion, sliced thin
- 1 tablespoon drained capers
- 2 bunches watercress, tough stems removed and leaves chopped
- 2 tablespoons olive oil
- 1 tablespoon red- or white-wine vinegar
- 3/4 teaspoon salt
- 1 teaspoon fresh-ground black pepper
- Put the tuna with its oil, the beans, onion, capers, watercress, olive oil, vinegar, salt, and pepper in a large bowl. Toss gently to combine.