Spaghetti with Tomatoes, Basil, Olives, and Fresh Mozzarella

Ingredients

• halved and pitted black olives
• teaspoons balsamic vinegar
• teaspoons salt
• teaspoon fresh-ground black pepper
• pound spaghetti
• olive oil
• garlic, minced
• pounds vine-ripened tomatoes , chopped
• pound salted fresh mozzarella, cut into 1/4-inch cubes, at room temperature
• chopped fresh basil