Bring a large pot of water to a boil. Add pasta and cook according to package directions. Rinse with cool water, drain and set aside.
Whisk vinegar, garlic, oregano, salt and pepper in a large bowl. Whisk in oil in a slow, steady stream until emulsified.
Add cherry tomatoes, chopped tomato, mozzarella, salami, basil and shallot to the bowl; toss to coat. Add the pasta and arugula and toss again. Garnish with basil, if desired.
