Fill a large pot halfway with water, cover, and bring to a boil. Uncover, add salt and pasta, and stir for a few seconds. Cook until desired firmness, 8-10 minutes.
Peel and mince garlic.
Peel and halve the shallots lengthwise, then thinly slice crosswise into half-rounds.
To make the dressing, add garlic, shallots, balsamic vinegar, olive oil, salt, and pepper to a medium bowl. Whisk to combine; set aside.
Wash and dry the fresh produce. (Skip the arugula if it came pre-washed.)
Halve the grape tomatoes lengthwise and add to a large bowl.
Cut the fresh mozzarella into bite-sized pieces and add to the bowl.
When pasta is done, drain in a colander, and rinse under cold water to cool; set aside to drain further.
Pick basil leaves off the stems, roll up crosswise, and thinly slice into ribbons. Add half of the basil to the bowl with the tomatoes and mozzarella; reserve the rest for garnish.
Add the pasta to the bowl and toss to combine.
To serve, divide the arugula between plates or bowls, and top with pasta salad. Drizzle balsamic vinaigrette over salad and sprinkle with remaining basil. Enjoy!