Finely mince the shallot and add it to the bottom of a large salad bowl. Pour the red wine vinegar on top and swirl bowl around so the shallots are all covered. Set aside for a few minutes while you prep the other ingredients.
If using small balls of mozzarella slice them in half and add them on top of the shallots followed by the tomatoes and orzo.
Spoon the herby oil mixture over the orzo, I start with 4 large spoonfuls, saving the rest to add to taste.
Thinly slice the basil and sprinkle that on top of the orzo.
Gently toss everything together, adding salt and pepper to taste.
Add more herby oil or vinegar as needed to taste.