Chop the heirloom tomatoes and finely grate a small clove of garlic. Put them in a bowl, season with salt and pepper, add basil leaves and a generous pour of olive oil. Toss to coat and set aside.
In the meantime, cook the Tortelloni according to package instructions and drain. Transfer the pasta to the bowl with tomato mixture and toss to coat. Garnish with additional basil leaves, olive oil, and shaved ricotta salata.