Note: Bread can be toasted in the oven or grilled.
Leaving the skin on, cut each tomato in half. Using your fingers or a spoon, remove and discard the seeds and excess liquid. Chop tomatoes into quarter-inch chunks. In a medium bowl, lightly toss tomatoes, 1 tablespoon olive oil, minced garlic, 1/2 teaspoon salt, 1/4 teaspoon black pepper, and balsamic vinegar. Refrigerate.
Preheat oven to 450 F. Cut the Italian loaf into ½-inch-thick slices. Lightly brush both sides with remaining olive oil. Lay each slice flat on a cookie sheet. Rub garlic halves across the top of the bread and sprinkle tops with remaining salt and pepper. Bake until lightly browned, about 5 minutes per side.
Stack basil leaves on top of each other, roll up like a cigar, then thinly slice with a sharp knife. Add basil to tomato mixture right before serving.
Top bread with tomatoes; serve immediately.
Per serving: 187 calories, 11 grams fat (2 grams saturated fat), 0 milligrams cholesterol, 532 grams sodium, 20 grams total carbohydrates, 4 grams fiber, 4 grams protein.