Dice the onion, avocado flesh and tomato and add to a mixing bowl. Roughly chop the cilantro and add to the bowl along with the lemon juice, half the olive oil and a pinch of salt and pepper. Stir to combine.
Step 2
Slice the mozzarella into half inch discs and arrange on a serving dish or platter. Season with a little salt and pepper and drizzle with the remaining oil.
Step 3
Spoon the salsa over the top of the sliced mozzarella to serve.