Dice your tomatoes into large ½" chunks. Place in your serving bowl and sprinkle generously with salt to begin drawing water out while you prep the other ingredients.
Slice the mozzarella and avocado into large ½" chunks. Add to the tomatoes.
Drizzle with a glug of olive oil (about 2 TBSP) and freshly cracked black pepper. Toss gently to combine.Adjust salt and pepper to taste.
Immediately before serving, thinly slice (chiffonade) 5-6 fresh basil leaves, add to the salad, and stir to combine. Serve with balsamic vinegar on the side for people to drizzle on their own, if desired.
This salad is best same day, as the avocados begin to brown rather quickly.