Cut the avocado in half, and hollow out each half, set aside the skin for later (sprinkle a little lemon juice on the inside of the skins to prevent browning).
Place the avocado flesh into a bowl and drizzle with fresh lemon juice
Finely dice red onion to taste and add to the bowl of avocado flesh.
Slice the mozzarella peals into quarters, the same for the cherry tomatoes.
Mix the avocado flesh and red onion until smooth.
Place some of the avocado mixture in the bottom of each avocado skin. layer the sliced tomatoes and mozzarella until all the ingredients are accounted for. Try to leave some mozzarella and tomatoes to sit on top for a splash of colour.
Drizzle with a little balsamic vinegar to taste
Rip the basil leaf with your fingers and use to lightly garnish the salad.