Warm focaccia, if desired. Spread avocado basil pesto on both slices of the bread.
Top with vegan mozzarella, slices of tomato, and fresh basil.
Notes
I suggest making the sandwiches right before serving, but if needed you can make them the day before. The Avocado Basil Pesto will last 3-5 days in the fridge. Since it will turn brown from oxidization, mix it well when eating leftovers. This will bring forth the greener parts underneath to the forefront.