Add the penne to a large pan or skillet and add 3 cups of cold water.

Turn the stove top burner on high and cook, stirring occasionally, for 10 minutes, until the water is nearly all gone.

Once the pasta is cooked and the water is evaporated, remove from the hot burner and add the pesto sauce. Mix well.

Add the halved tomatoes and the mozzarella balls to the hot pasta and mix well. Serve immediately garnished with basil, if desired.