Cook the Tortelloni according to package instructions. In the meantime, heat the tomato sauce with half of the basil leaves and milk on a low heat; season with salt and pepper adding pasta water a little at a time if you need to loosen the sauce.
Drain Tortelloni and season with half of the oil. Divide the tomato sauce between 2 soup plates. Top with Tortelloni, drizzle with the remaining oil, season with pepper, sprinkle with Parmigiano Reggiano cheese, garnish with the remaining basil leaves and serve.