1 Whisk together the balsamic vinegar, 3 tablespoons water, salt and pepper to taste, and olive oil.
2 Drain mozzarella and cut into slices.
3 Remove melon seeds with a spoon and scoop out flesh from the shell with a melon baller.
4 Pick over raspberries, then gently rinse and drain well.
5 Rinse the romaine lettuce, spin dry and separate leaves, tearing larger ones in half. Toss with about 2/3 of the dressing and season with salt and pepper.
6 Divide romaine, mozzarella, melon and raspberries among plates, drizzle with remaining dressing and serve immediately.