Finely chop the basil and garlic, then add them to the tomatoes along with the balsamic vinegar, sea salt, ground pepper, and about 1/2 tablespoon of olive oil.
Preheat the oven to 400°F (200°C) and line a baking tray with parchment paper. Slice the bread and brush each slice with the remaining 1 1/2 tablespoons of olive oil.
If you plan to serve the bruschetta immediately, arrange the toasted bread on a platter, topped with a little of the tomato mixture, and drizzle with extra olive oil or a balsamic glaze.