Cut the tomato and mozzarella into similar-sized slices and arrange them on a plate in an alternating, interleaved pattern. Drizzle some pesto sauce on top.
To make the pesto sauce, first blanch the basil leaves for 10 seconds in a pan of boiling water and then plunge them into a bowl of ice water. Once the leaves have cooled, dry them thoroughly and blend together with the other ingredients.