1.Preheat oven to 220°C/425°F.
2.Combine tomato and vinegar in a small shallow baking dish. Place prosciutto on oven tray. Roast, uncovered, for 10 minutes or until tomato softens and prosciutto is crisp.
3.Spread cheese over toast; top with tomato, prosciutto and basil. Season to taste.
If taking this meal to work, roast tomato and prosciutto the night before; store in the fridge. Reheat in a microwave oven, on HIGH (100%), about 1 minute or until heated through. Toast the bread and assemble just before serving.Note