Whisk 3 tablespoons vinegar, 2 tablespoons oil, 2 teaspoons mustard, the grated garlic, ¼ teaspoon salt and ¼ teaspoon pepper together in a large bowl.
Add rinsed chickpeas, halved tomatoes, sliced cucumbers, 1 cup mozzarella and ¼ cup basil; toss to coat.
Refrigerate until ready to serve.
