Bocconcini are the smaller fresh mozarrella cheese sold in brine. They are much tenderer and worth the exttra money. This is a nice variation of the usual salad.
To prepare the dressing, place tomato in a blender or food processor fitted with the metal blade and process to a textured pure. Add remaining ingredients and pulse to just combine.
Arrange the tomato and cheese slices in alternate layers on 4 small plates. Spoon the dressing over and serve immediately.