For the balsamic caramel, cut the vanilla pod lengthwise and scrape out the pulp. Melt the sugar at medium heat in a pan until it caramelises. Deglaze with balsamic vinegar. Add the vanilla pulp and pod.
Season with salt and pepper. Simmer the caramel until it has dissolved and is syrupy.
For the light vinaigrette, mix olive oil, wine vinegar, a little salt and pepper. Peel the mango. Cut the flesh first from the stone, then into small cubes. Wash and quarter the tomatoes. Mix the mango and tomatoes with half of the light vinaigrette each.
Wash, clean and dry the salad. Cut mozzarella into half slices and dab dry.
Layer mango, tomatoes, lettuce and mozzarella alternately in six glasses (each containing approx. 300 ml). Remove the vanilla pod from the balsamic caramel. Dribble over the trifle.