Cook the pasta according to package instructions until al dente. Drain and rinse under cold water.

In a large mixing bowl, combine the cooked pasta, tuna, cherry tomatoes, cucumber, red onion, and black olives.

In a small bowl, whisk together the olive oil, lemon juice, dijon mustard, minced garlic, salt, and pepper.

Pour the dressing over the pasta mixture and toss to combine. Garnish with fresh parsley and serve chilled or at room temperature.