- 1 small red onion, thinly sliced
- 2 tablespoons red wine vinegar
- 2 small fennel bulbs, trimmed and diced (about 2 cups)
- 1/2 pound green beans, trimmed and diced
- 1/2 pound carrots (about 3 carrots), peeled and diced
- 1 15 1/2-ounce can chickpeas, drained
- 1 pint cherry tomatoes, halved
- 1 head radicchio, shredded
- 6 tablespoons olive oil
- kosher salt and black pepper
- 2 6-ounce cans tuna in oil
- 2 tablespoons chopped, fresh flat-leaf parsley
- Mix the onion and vinegar in a small bowl. Cover and set aside for 10 minutes, stirring halfway through.
- Combine the fennel, green beans, carrots, chickpeas, tomatoes, and radicchio in a large bowl. Gently toss.
- Drain the onion slices, reserving the vinegar. Whisk the reserved vinegar with the olive oil. Add 1 ¼ tablespoons salt and ½ teaspoon pepper.
- Drain the tuna and flake it into large chunks in a medium bowl. Toss with half the onion slices, 2 tablespoons of the vinaigrette, and the parsley.
- Toss the remaining vinaigrette and onion with the chopped vegetables. Divide the vegetables among 4 serving bowls and top with the dressed tuna.