Stir together the red onion, garlic, chopped basil, extra-virgin olive oil, sherry vinegar, tomatoes, and plenty of salt and pepper to taste in a mixing bowl. Cover and set aside for 10 minutes to let the flavors develop.
In the meantime, preheat the broiler to high heat. Turn broiler down to low heat, and add the bread slices to a high rack. Toast the bread under the broiler until golden (7-9 minutes), turning once.
Remove from the broiler to a platter. Top with spoonfuls of the bruschetta mixture and serve.
Article source: https://ohmyveggies.com/bruschetta-summer-tomatoes-basil/