With the rack in the middle position, preheat the oven to 400ºF (200ºC).
In a glass or ceramic baking dish, drizzle the tomatoes and garlic with two tablespoons (30 milliliters) of the olive oil. Season generously with salt and pepper. Bake for 20 minutes or until the tomatoes are tender and have burst slightly. Remove from the oven.
Transfer to a serving platter. Add the remaining oil and drizzle with the vinegar.
Serve the tomatoes as an appetizer with bread for dipping in the oil and vinegar dressing.