Unroll your mozzarella and arrange a layer of tomato slices in a manner that will still allow you to roll when complete.
Season tomatoes very well with S&P, and if you like a bit of spice I recommend some crushed red pepper flakes. Now place a healthy layer of basil on top of everything.
Now drizzle EVOO liberally and balsamic vinegar if desired. Season again with salt and pepper and roll as tightly as possible. Pin shut with some bamboo skewers or something similar and let sit in the refrigerator to marinate your flavors a bit and firm up a bit.
When serving, slice the roll into ~1" long slices and use a toothpick to keep them shut. Perfect for any summer day.