Drizzle your baguette slices with olive oil, then top each slice with a thin small slice of mozzarella cheese.
Lightly toast your mozzarella topped baguettes in a toaster oven or in the oven at 350 degrees for about 5-7 minutes.
While your baguette slices are toasting; combine tomatoes, onions, garlic, basil, balsamic, black pepper and salt in a small bowl. Taste and add salt if needed, a pinch at a time.
When your baguette slices are done toasting, gently remove and let them cool slightly. Top each slice with about 1 tablespoon of the tomato mixture. You are ready to eat!