In a mixing bowl, combine diced cucumber, halved cherry tomatoes, and diced bell pepper.

In a separate small bowl, whisk together olive oil, balsamic vinegar, Dijon mustard, minced garlic, salt, and pepper.

Pour the dressing over the vegetable mixture and toss to coat evenly.

Transfer the salad to a serving platter and garnish with chopped basil and grated Parmesan cheese.