Combine tomatoes, onions, balsamic vinegar, garlic, salt, pepper, and 1 tsp olive oil in a bowl and mix to combine. Add basil and gently toss to distribute. Give it a taste and add additional salt and pepper if necessary.
Preheat oven to 400 degrees. Slice baguette into half inch slices and place on a baking sheet. Drizzle or brush some olive oil on top. Place in oven for 8-10 minutes until just lightly toasted. Remove pan from oven, let cool. Top with bruschetta and enjoy!
Wine Pairing: The summer flavors of bruschetta call out for summer wine. Try this with dry rosé or sauvignon blanc.