Mix together the olive oil, pesto and vinegar in a bowl.
On small skewers, thread 1 tortellini, 1 cherry tomato and 1 mozzarella cube per skewer. Lay the skewers on a platter and lightly drizzle the dressing over them with a spoon.
Serve immediately or refrigerate. Sprinkle on the minced parsley just before serving.
Recipe courtesy of Mario Batali