Preheat your oven's broiler.
Slice bread loaf into 1-inch thick portions. Brush each slice on one side with olive oil. Broil, oil-side up, until barely golden. Remove from broiler pan and cool.
In a medium bowl, mix together roasted pepper, garlic, tomato, basil, and onion. Sprinkle mixture evenly on each toast portion. Drizzle with balsamic vinegar. Serve immediately.
